drm/tests/drm_buddy: add alloc_contiguous test

Sanity check DRM_BUDDY_CONTIGUOUS_ALLOCATION.

v2: Fix checkpatch warnings.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240214131853.5934-2-Arunpravin.PaneerSelvam@amd.com


Signed-off-by: Christian König <christian.koenig@amd.com>