Fixes coccicheck warning:

drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c:4946:28-29: WARNING: Use ARRAY_SIZE
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>