drm/xe: Fix build without CONFIG_FAULT_INJECTION

drm/xe: Fix build without CONFIG_FAULT_INJECTION

Ideally this header could be included without the CONFIG_FAULT_INJECTION
and it would take care itself for the includes it needs.
So, let's temporary workaround this by moving this below and including
only when CONFIG_FAULT_INJECTION is selected to avoid build breakages.

Another solution would be us including the linux/types.h as well, but
this creates unnecessary cases.

Reference: https://lore.kernel.org/all/20230816134748.979231-1-himal.prasad.ghimiray@intel.com/
Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Cc: Oded Gabbay <ogabbay@kernel.org>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>