drm/xe/uapi: Reject bo creation of unaligned size

For xe bo creation we request passing size which matches system or
vram minimum page alignment. This way we want to ensure userspace
is aware of region constraints and not aligned allocations will be
rejected returning EINVAL.

v2:
- Rebase, Update uAPI documentation. (Thomas)
v3:
- Adjust the dma-buf kunit test accordingly. (Thomas)
v4:
- Fixed rebase conflicts and updated commit message. (Francois)

Signed-off-by: Mauro Carvalho Chehab <mauro.chehab@linux.intel.com>
Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>