kgpe: flashrom.layout no longer needed

Since a6cd35, ownerboot includes a patch to flashrom which allows
nested (but non-overlapping) fmap regions, so the flashrom.layout
file is no longer necessary.

src/platform/kgpe/default.nix

@@ -22,18 +22,9 @@
       config = ./coreboot.config;
       coreboot-toolchain = with final.coreboot-toolchain; [ x64 i386 ];
     }).overrideAttrs (a: {
-      # KGPE has an FMAP region "BIOS" which overlaps the whole flash;
-      # this is needed for some kind of protection mechanism in the
-      # SMBIOS.  Unfortunately it causes flashrom to choke.  So we have
-      # to feed flashrom a `flashrom.layout` file instead of letting it
-      # use the FMAP.
       postInstall = (a.postInstall or "") + ''
         cp src/mainboard/asus/kgpe-d16/cmos.layout $out/
         cp src/mainboard/asus/kgpe-d16/cmos.default $out/
-         cat > $out/flashrom.layout <<\EOF
-        00000400:007fffff NORMAL
-        00800400:00ffffff FALLBACK
-        EOF
     '';
     });
   });