drm/panfrost: Handle page mapping failure

drm/panfrost: Handle page mapping failure

When mapping the pages of a BO, either a heap type at page fault time or
else a non-heap BO at object creation time, if the ARM page table mapping
function fails, we unmap what had been mapped so far and bail out.

Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Link: https://lore.kernel.org/r/20251019145225.3621989-7-adrian.larumbe@collabora.com
Signed-off-by: Steven Price <steven.price@arm.com>