drm/msm/adreno: Remove MODULE_FIRMWARE()'s

The driver handles the case where gpu fw is not in the initrd.  OTOH it
doesn't always handle the case where _some_ fw is in the initrd, but
others are not.  In particular the zap fw tends to be signed with an OEM
specific key, so the paths/names differ across devices with the same
SoC/GPU, so we cannot sanely list them with MODULE_FIRMWARE().

So MODULE_FIRMWARE() just ends up causing problems without actually
solving anything.  Remove them!

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/652195/