drm/ttm: Add ttm_bo_kmap_try_from_panic()

If the ttm bo is backed by pages, then it's possible to safely kmap
one page at a time, using kmap_try_from_panic().
Unfortunately there is no way to do the same with ioremap, so it
only supports the kmap case.
This is needed for proper drm_panic support with xe driver.

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/r/20250624091501.257661-6-jfalempe@redhat.com


Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>