drm/i915: Switch the order of function parameters

intel_fb_pitch_limit() has the parameters pixel_format and fb_modifier
switched in their positions. The parameters are however used correctly,
but change the order for consistency.

Also use kernel data types for both parameters.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181026195342.16828-1-dhinakaran.pandiyan@intel.com