drm/xe: make compound literal initialization const

drm/xe: make compound literal initialization const

Be careful about having const in the compound literal initialization to
keep the initializers in rodata. Here, the impact is 1.8k of mutable
data moved to rodata.

add/remove: 0/1 grow/shrink: 0/0 up/down: 0/-1804 (-1804)
Data                                         old     new   delta
__compound_literal                          1804       -   -1804
Total: Before=42425, After=40621, chg -4.25%
add/remove: 0/0 grow/shrink: 1/0 up/down: 1804/0 (1804)
RO Data                                      old     new   delta
__compound_literal                          7696    9500   +1804
Total: Before=138535, After=140339, chg +1.30%

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20230309121746.479146-1-jani.nikula@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>