linux_chromiumos_3_18: remove kernel due lack of maintainer/breakage

There is no maintainer for this package, probably not many users.
It requires effort to fix all third-party modules for this old kernel
versions. It might contain unpatched security holes.

For Pixel chromebooks, we have the samus-kernel.
Apart from that https://github.com/GalliumOS/linux might be a good choice.

pkgs/os-specific/linux/acpi-call/default.nix

@@ -24,7 +24,7 @@ stdenv.mkDerivation {
     sed -e "s@/lib/modules/\$(.*)@${kernel.dev}/lib/modules/${kernel.modDirVersion}@" -i Makefile
     sed -e 's@acpi/acpi[.]h@linux/acpi.h@g' -i acpi_call.c
   '';
- 
+
   installPhase = ''
     mkdir -p $out/lib/modules/${kernel.modDirVersion}/misc
     cp acpi_call.ko $out/lib/modules/${kernel.modDirVersion}/misc
@@ -37,6 +37,5 @@ stdenv.mkDerivation {
     maintainers = [stdenv.lib.maintainers.raskin];
     platforms = stdenv.lib.platforms.linux;
     description = "A module allowing arbitrary ACPI calls; use case: hybrid video";
-    broken = kernel.features.chromiumos or false;
   };
 }