This attempts to mitigate <https://issues.guix.gnu.org/52667>.
It makes linux-libre@5.15 consistent with older versions which do not
support a modular simplefb, allowing a single %base-initrd-modules
simple list for all of them.
Unlike CONFIG_FB_SIMPLE=m, CONFIG_FB_SIMPLE=y conflicts with
CONFIG_DRM_SIMPLEDRM, so the latter is now disabled. Let us hope it is
not missed.
* gnu/packages/aux-files/linux-libre/5.15-i686.conf,
gnu/packages/aux-files/linux-libre/5.15-x86_64.conf:
Unset CONFIG_DRM_SIMPLEDRM to build in CONFIG_FB_SIMPLE=y.
* gnu/system/linux-initrd.scm (default-initrd-modules):
Remove "simplefb".