drm/i915/dg2: Implement Wa_14022698537

drm/i915/dg2: Implement Wa_14022698537

G8 power state entry is disabled due to a limitation on DG2, so we
enable it from driver with Wa_14022698537. For now we enable it for
all DG2 devices with the exception of a few, for which, we enable
only when paired with whitelisted CPU models. This works with native
ASPM and reduces idle power consumption.

$ echo powersave > /sys/module/pcie_aspm/parameters/policy
$ lspci -s 0000:03:00.0 -vvv
LnkCtl: ASPM L1 Enabled; RCB 64 bytes, Disabled- CommClk-

v2: Fix Wa_ID and include it in subject (Badal)
    Rephrase commit message (Jani)
v3: Move workaround to i915_pcode_init() (Badal, Anshuman)
    Re-order macro (Riana)
v4: Spell fix (Riana)

Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Riana Tauro <riana.tauro@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241211115952.1659287-5-raag.jadav@intel.com