drm/xe: Encapsulate all the module parameters

drm/xe: Encapsulate all the module parameters

Encapsulate all the module parameters in one single global struct
variable. This also removes the extra xe_module.h from includes.

v2: naming consistency as suggested by Jani and Lucas
v3: fix checkpatch errors/warnings
v4: adding blank line after struct declaration

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Bommithi Sakeena <bommithi.sakeena@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>