drm/amd/display: Fix boolean expression in get_surf_rq_param

Fix boolean expression by using logical AND operator '&&'
instead of bitwise operator '&'.

This issue was detected with the help of Coccinelle.

Fixes: 6d04ee9d ("drm/amd/display: Restructuring and cleaning up DML")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>