drm/komeda: Fix bit check to import to value of proper type

KASAN found this problem. find_first_bit() expects to look at a
pointer pointing to a long, but we look at a u32 - this is going to be
an issue with endianness but, KSAN already flags this as out-of-bounds
stack reads. This fixes it by just importing inot a local long.

Signed-off-by: Carsten Haitzler <carsten.haitzler@arm.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201218150812.68195-1-carsten.haitzler@foss.arm.com