drm/i915/pcode: Add a couple of pcode helpers

drm/i915/pcode: Add a couple of pcode helpers

Some dGfx pcode commands take additional sub-commands and parameters. Add a
couple of helpers to help formatting these commands to improve code
readability.

v2: Fixed commit author (Rodrigo)
v3: Function rename and convert to new uncore interface for pcode functions
    Remove unnecessary #define's (Andi)
v4: Another function rename

Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: Dale B Stimson <dale.b.stimson@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220519085732.1276255-3-tvrtko.ursulin@linux.intel.com