Use sky130_ef_sc_hd__decap_12 for fill generation

Tim suggests we use the modified sky130_ef_sc_hd__decap_12 for fill
generation to avoid local interconnect density issues.

Also use a wildcard to select all the sky130_fd_sc_hd__fill cells. While
what we have seems to work, the OpenROAD documentation says to use
wildcard matching.

sky130/openlane/sky130_fd_sc_hd/config.tcl

diff --git a/sky130/openlane/sky130_fd_sc_hd/config.tcl b/sky130/openlane/sky130_fd_sc_hd/config.tcl
index f9947a5..26bea27 100755
--- a/sky130/openlane/sky130_fd_sc_hd/config.tcl
+++ b/sky130/openlane/sky130_fd_sc_hd/config.tcl
@@ -47,8 +47,8 @@
 set ::env(PL_LIB) $::env(LIB_TYPICAL)
 
 # Fillcell insertion
-set ::env(FILL_CELL) "sky130_fd_sc_hd__fill_"
-set ::env(DECAP_CELL) "sky130_fd_sc_hd__decap_"
+set ::env(FILL_CELL) "sky130_fd_sc_hd__fill*"
+set ::env(DECAP_CELL) "sky130_ef_sc_hd__decap_12 sky130_fd_sc_hd__decap_8 sky130_fd_sc_hd__decap_6 sky130_fd_sc_hd__decap_4 sky130_fd_sc_hd__decap_3"
 set ::env(RE_BUFFER_CELL) "sky130_fd_sc_hd__buf_4"
 
 # Diode insertaion
@@ -57,7 +57,7 @@
 set ::env(DIODE_CELL_PIN) "DIODE"
 
 set ::env(CELL_PAD) 4
-set ::env(CELL_PAD_EXCLUDE) "sky130_fd_sc_hd__tap* sky130_fd_sc_hd__decap* sky130_fd_sc_hd__fill*"
+set ::env(CELL_PAD_EXCLUDE) "sky130_fd_sc_hd__tap* sky130_fd_sc_hd__decap* sky130_ef_sc_hd__decap* sky130_fd_sc_hd__fill*"
 
 # Clk Buffers info CTS data
 set ::env(ROOT_CLK_BUFFER) sky130_fd_sc_hd__clkbuf_16