drm/i915/rkl: Add Wa_14011224835 for PHY B initialization

drm/i915/rkl: Add Wa_14011224835 for PHY B initialization

After doing normal PHY-B initialization on Rocket Lake, we need to
manually copy some additional PHY-A register values into PHY-B
registers.

Note that the bspec's combo phy page doesn't specify that this
workaround is restricted to specific platform steppings (and doesn't
even do a very good job of specifying that RKL is the only platform this
is needed on), but the RKL workaround page lists this as relevant only
for A and B steppings, so I'm trusting that information for now.

v2:  Make rkl_combo_phy_b_init_wa() static

v3:
 - Minimize variables in WA function. (Jose)
 - Fix timeout duration (usec vs msec). (Jose)
 - Add verification of workaround. (Jose)
 - Fix stepping bounds in comment.

Bspec: 49291
Bspec: 53273
Cc: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200716220551.2730644-6-matthew.d.roper@intel.com
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>