Fix `CLASS` for fill_diode LEF files.

Replace `CLASS SPACER` with `CLASS CORE SPACER`.

Fixes https://github.com/google/skywater-pdk/issues/141.

Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>

cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.lef

diff --git a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.lef b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.lef
index 38cc2b4..91f2db3 100644
--- a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.lef
+++ b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.lef
@@ -19,7 +19,7 @@
   DIVIDERCHAR "/" ;
   BUSBITCHARS "[]" ;
 MACRO sky130_fd_sc_ms__fill_diode_2
-  CLASS SPACER ;
+  CLASS CORE SPACER ;
   FOREIGN scs8ms_fill_diode_2 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.960000 BY  3.330000 ;

cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.magic.lef

diff --git a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.magic.lef b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.magic.lef
index ae8bc5a..95278d0 100644
--- a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.magic.lef
+++ b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.magic.lef
@@ -19,7 +19,7 @@
   DIVIDERCHAR "/" ;
   BUSBITCHARS "[]" ;
 MACRO sky130_fd_sc_ms__fill_diode_2
-  CLASS SPACER ;
+  CLASS CORE SPACER ;
   FOREIGN sky130_fd_sc_ms__fill_diode_2 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.960000 BY  3.330000 ;

cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.lef

diff --git a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.lef b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.lef
index 8bcae67..ddd052f 100644
--- a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.lef
+++ b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.lef
@@ -19,7 +19,7 @@
   DIVIDERCHAR "/" ;
   BUSBITCHARS "[]" ;
 MACRO sky130_fd_sc_ms__fill_diode_4
-  CLASS SPACER ;
+  CLASS CORE SPACER ;
   FOREIGN scs8ms_fill_diode_4 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  1.920000 BY  3.330000 ;

cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.magic.lef

diff --git a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.magic.lef b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.magic.lef
index b8b4101..aad6c7d 100644
--- a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.magic.lef
+++ b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.magic.lef
@@ -19,7 +19,7 @@
   DIVIDERCHAR "/" ;
   BUSBITCHARS "[]" ;
 MACRO sky130_fd_sc_ms__fill_diode_4
-  CLASS SPACER ;
+  CLASS CORE SPACER ;
   FOREIGN sky130_fd_sc_ms__fill_diode_4 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  1.920000 BY  3.330000 ;

cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.lef

diff --git a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.lef b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.lef
index 35fbee3..825a112 100644
--- a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.lef
+++ b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.lef
@@ -19,7 +19,7 @@
   DIVIDERCHAR "/" ;
   BUSBITCHARS "[]" ;
 MACRO sky130_fd_sc_ms__fill_diode_8
-  CLASS SPACER ;
+  CLASS CORE SPACER ;
   FOREIGN scs8ms_fill_diode_8 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  3.840000 BY  3.330000 ;

cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.magic.lef

diff --git a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.magic.lef b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.magic.lef
index 7733ad8..3b37efe 100644
--- a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.magic.lef
+++ b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.magic.lef
@@ -19,7 +19,7 @@
   DIVIDERCHAR "/" ;
   BUSBITCHARS "[]" ;
 MACRO sky130_fd_sc_ms__fill_diode_8
-  CLASS SPACER ;
+  CLASS CORE SPACER ;
   FOREIGN sky130_fd_sc_ms__fill_diode_8 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  3.840000 BY  3.330000 ;