drm/amdgpu: fix UVD contiguous CS mapping problem

When starting the mpv player, Radeon R9 users are observing
the below error in dmesg.

[drm:amdgpu_uvd_cs_pass2 [amdgpu]]
*ERROR* msg/fb buffer ff00f7c000-ff00f7e000 out of 256MB segment!

The patch tries to set the TTM_PL_FLAG_CONTIGUOUS for both user
flag(AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS) set and not set cases.

v2: Make the TTM_PL_FLAG_CONTIGUOUS mandatory for user BO's.
v3: revert back to v1, but fix the check instead (chk).

Closes:drm/amd#3599
Closes:drm/amd#3501


Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Cc: stable@vger.kernel.org # 6.10+