Adjusted fill for m1 to m4 from 0.6um spacing to 0.8um spacing for
the coarse fill patterns;  maximum density reduced from 59% to 51%
which should prevent failing full chip density.
diff --git a/sky130/magic/sky130.tech b/sky130/magic/sky130.tech
index f0683f4..e9ee04d 100644
--- a/sky130/magic/sky130.tech
+++ b/sky130/magic/sky130.tech
@@ -1977,7 +1977,7 @@
         grow    3000
  templayer	met1fill_coarse topbox
         # slots   0 2000 200 0 2000 200 700 0
-        slots   0 2000 600 0 2000 600 700 350
+        slots   0 2000 800 0 2000 800 700 350
         and-not obstruct_m1_coarse
 	and	topbox
         shrink  995
@@ -2029,7 +2029,7 @@
         grow    3000
  templayer	met2fill_coarse topbox
         # slots   0 2000 200 0 2000 200 700 350
-        slots   0 2000 600 0 2000 600 700 350
+        slots   0 2000 800 0 2000 800 700 350
         and-not obstruct_m2
 	and	topbox
         shrink  995
@@ -2081,7 +2081,7 @@
         grow    3000
  templayer	met3fill_coarse topbox
         # slots   0 2000 300 0 2000 300 700 700
-        slots   0 2000 600 0 2000 600 700 350
+        slots   0 2000 800 0 2000 800 700 350
         and-not obstruct_m3
 	and	topbox
         shrink  995
@@ -2135,7 +2135,7 @@
         grow    3000
  templayer	met4fill_coarse topbox
         # slots   0 2000 300 0 2000 300 700 1050
-        slots   0 2000 600 0 2000 600 700 350
+        slots   0 2000 800 0 2000 800 700 350
         and-not obstruct_m4
 	and	topbox
         shrink  995