drm/i915/rkl: provide port/phy mapping for vbt

RKL uses the DDI A, DDI B, DDI USBC1, DDI USBC2 from the DE point of
view, so all DDI/pipe/transcoder register use these indexes to refer to
them. Combo phy and IO functions follow another namespace that we keep
as "enum phy". The VBT in theory would use the DE point of view, but
that does not happen in practice.

Provide a table to convert the child devices to the "correct" port
numbering we use. Now this is the output we get while reading the VBT:

DDIA:
[drm:intel_bios_port_aux_ch [i915]] using AUX A for port A (VBT)
[drm:intel_dp_init_connector [i915]] Adding DP connector on [ENCODER:275:DDI A]
[drm:intel_hdmi_init_connector [i915]] Adding HDMI connector on [ENCODER:275:DDI A]
[drm:intel_hdmi_init_connector [i915]] Using DDC pin 0x1 for port A (VBT)

DDIB:
[drm:intel_bios_port_aux_ch [i915]] using AUX B for port B (platform default)
[drm:intel_hdmi_init_connector [i915]] Adding HDMI connector on [ENCODER:291:DDI B]
[drm:intel_hdmi_init_connector [i915]] Using DDC pin 0x2 for port B (VBT)

DDI USBC1:
[drm:intel_bios_port_aux_ch [i915]] using AUX D for port D (VBT)
[drm:intel_dp_init_connector [i915]] Adding DP connector on [ENCODER:295:DDI D]
[drm:intel_hdmi_init_connector [i915]] Adding HDMI connector on [ENCODER:295:DDI D]
[drm:intel_hdmi_init_connector [i915]] Using DDC pin 0x3 for port D (VBT)

DDI USBC2:
[drm:intel_bios_port_aux_ch [i915]] using AUX E for port E (VBT)
[drm:intel_dp_init_connector [i915]] Adding DP connector on [ENCODER:306:DDI E]
[drm:intel_hdmi_init_connector [i915]] Adding HDMI connector on [ENCODER:306:DDI E]
[drm:intel_hdmi_init_connector [i915]] Using DDC pin 0x9 for port E (VBT)

Cc: Clinton Taylor <Clinton.A.Taylor@intel.com>
Cc: Aditya Swarup <aditya.swarup@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200603211529.3005059-7-matthew.d.roper@intel.com