drm/i915: Make I915_PARAMS_FOR_EACH macro more flexible

We should not add trailing ; after each member to allow other
than statements-style uses of this helper macro.
While here s/func/param for clarity.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170925105008.46060-1-michal.wajdeczko@intel.com