drm/amd/display: Drop FPU flags from dml21_wrapper.c

drm/amd/display: Drop FPU flags from dml21_wrapper.c

[WHAT]
The existing CFLAGS_ lines were pointing to a wrong location
for dml21_wrapper.c and were thereby ineffective. This means
dml21_wrapper.c is not an FPU compilation unit. Remove the
(erroneous) CFLAGS_ entries.

Reviewed-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>