drm/xe/pf: Use div_u64 when calculating GGTT profile

This will fix the following error seen on some 32-bit config:

"ERROR: modpost: "__udivdi3" [drivers/gpu/drm/xe/xe.ko] undefined!"

Reported-by: kernel test robot <[e-mail]>
Closes: https://lore.kernel.org/oe-kbuild-all/[e-mail]/
Fixes: e448372e8a8e ("drm/xe/pf: Use migration-friendly GGTT auto-provisioning")
Signed-off-by: Michal Wajdeczko <[e-mail]>
Reviewed-by: Piotr Piórkowski <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
(cherry picked from commit 0f4435a1f46efc3177eb082cd3f73e29da5ab86a)
Signed-off-by: Thomas Hellström <[e-mail]>

drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c

···
 	if (num_vfs > 56)
 		return SZ_64M - SZ_8M;
 
-	return rounddown_pow_of_two(shareable / num_vfs);
+	return rounddown_pow_of_two(div_u64(shareable, num_vfs));
 }
 
 /**