drm/xe: avoid plain 64-bit division

drm/xe: avoid plain 64-bit division

Building the xe driver for i386 results in a link time warning:

x86_64-linux-ld: drivers/gpu/drm/xe/xe_migrate.o: in function `xe_migrate_vram':
xe_migrate.c:(.text+0x1e15): undefined reference to `__udivdi3'

Avoid this by using DIV_U64_ROUND_UP() instead of DIV_ROUND_UP().  The driver
is unlikely to be used on 32=bit hardware, so the extra cost here is not
too important.

Fixes: 9c44fd5f6e8a ("drm/xe: Add migrate layer functions for SVM support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20250324210612.2927194-1-arnd@kernel.org
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>