drm/i915/psr: Calculate IO wake and fast wake lines for DISPLAY_VER < 12

drm/i915/psr: Calculate IO wake and fast wake lines for DISPLAY_VER < 12

Bspec mentions 50 us for IO wake time and 32 us for fast wake time. 32 us
is most probably wrong as it doesn't meet the specification as fast wake
time is calculated in Bspec like this:

10..16 us (precharge) + 8 us (preamble) + 4 us (phy_wake) + 20 us
(tfw_exit_latency)

Instead of using these constants calculate IO wake and fast wake for
DISPLAY_VER < 12 as well.

v3:
  - do not handle < 9 separately
  - add own helper for skl and tgl io buffer wake times
v2:
  - initialize io/fast_wake_time for display version < 9

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240313133221.868391-4-jouni.hogander@intel.com