drm/i915/adlp/fb: Remove restriction on CCS AUX plane strides

As opposed to other GEN12 platforms ADLP provides a way to program the
stride of CCS surfaces independently of the main surface stride (within
the corresponding limit of the preceding and succeeding power-of-two
values of the main surface stride). Using this HW feature we can remove
the POT stride restriction on CCS surfaces, making the ADLP CCS FB uAPI
(FB modifiers) identical to that of TGL.

The HW makes the CCS stride flexible programming possible by deriving
the stride from the value programmed to the PLANE_STRIDE register. After
that the HW rounds up this value to the next power-of-two value and uses
this for walking the pages of the main surface mapped to GTT/DPT.

To align with the above scheme, introduce a scanout_stride view
parameter which will be programmed to the PLANE_STRIDE register and use
the mapping_stride view param to store the POT aligned value of the
same. By requiring userspace to pass in FBs with a CCS stride that
aligns with the main surface stride (matching the requirement of all
GEN12 platforms), the scanout_stride will be the userspace main surface
stride and the mapping_stride will be the POT rounded value of the same.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Cc: Nanley G Chery <nanley.g.chery@intel.com>
Cc: Sameer Lattannavar <sameer.lattannavar@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211026225105.2783797-8-imre.deak@intel.com