drm/i915/dsi: add support for ICL+ native MIPI GPIO sequence

drm/i915/dsi: add support for ICL+ native MIPI GPIO sequence

Starting from ICL, the default for MIPI GPIO sequences seems to be using
native GPIOs i.e. GPIOs available in the GPU. These native GPIOs reuse
many pins that quite frankly seem scary to poke based on the VBT
sequences. We pretty much have to trust that the board is configured
such that the relevant HPD, PP_CONTROL and GPIO bits aren't used for
anything else.

MIPI sequence v4 also adds a flag to fall back to non-native sequences.

v5:
- Wrap SHOTPLUG_CTL_DDI modification in spin_lock() in icp_irq_handler()
  too (Ville)
- References instead of Closes issue 6131 because this does not fix everything

v4:
- Wrap SHOTPLUG_CTL_DDI modification in spin_lock_irq() (Ville)

v3:
- Fix -Wbitwise-conditional-parentheses (kernel test robot <lkp@intel.com>)

v2:
- Fix HPD pin output set (impacts GPIOs 0 and 5)
- Fix GPIO data output direction set (impacts GPIOs 4 and 9)
- Reduce register accesses to single intel_de_rwm()

References: https://gitlab.freedesktop.org/drm/intel/-/issues/6131
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221219105955.4014451-1-jani.nikula@intel.com