drm/{i915, xe}/reg: rename masked field helpers REG_MASKED_FIELD*()

drm/{i915, xe}/reg: rename masked field helpers REG_MASKED_FIELD*()

The underscore prefixed masked field helper names aren't great. Rename
them REG_MASKED_FIELD(), REG_MASKED_FIELD_ENABLE(), and
REG_MASKED_FIELD_DISABLE(). This is more in line with the existing
REG_FIELD_PREP() etc. helpers, and using "field" instead of "bit" is
more accurate for the functionality.

This is done with:

sed -i 's/_MASKED_FIELD/REG_MASKED_FIELD/g' $(git grep -wl _MASKED_FIELD)
sed -i 's/_MASKED_BIT_ENABLE/REG_MASKED_FIELD_ENABLE/g' $(git grep -wl _MASKED_BIT_ENABLE)
sed -i 's/_MASKED_BIT_DISABLE/REG_MASKED_FIELD_DISABLE/g' $(git grep -wl _MASKED_BIT_DISABLE)

with some manual indentation fixes on top.

Reviewed-by: Michał Grzelak <michal.grzelak@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patch.msgid.link/49dc20448a12f3e03f5f8347540d167a281b8987.1772042022.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>