drm/i915/dmc_wl: store register ranges in rodata

Add const to register range arrays to store them in rodata. They don't
need to be modified.

Cc: Gustavo Sousa <gustavo.sousa@intel.com>
Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241218141734.2583601-1-jani.nikula@intel.com


Signed-off-by: Jani Nikula <jani.nikula@intel.com>