drm/xe: Relocate regs_are_mcr function

Relocate regs_are_mcr funciton to a higher position in the file
for improved visibility.

Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Janga Rahul Kumar <janga.rahul.kumar@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240503193902.2056202-2-janga.rahul.kumar@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>