usb: typec: altmodes/displayport: add SOP' support

Implement active cable VDM support for SOP' according to the DisplayPort
Alt Mode 2.0 specification.

When probing the DisplayPort driver, the state machine will transition to
Enter Mode on SOP' if an active cable altmode is detected. The SVDM flow
is as followed:
    (1) Enter Mode     SOP'
    (2) Enter Mode     SOP
    (3) Status Update  SOP
    (4) Configure      SOP'
    (5) Configure      SOP

Status Update on SOP' after Enter Mode is optional and not implemented for
now. When exiting the alt mode, send Exit Mode over SOP' after SOP.

Should an altmode vdm fail on SOP', the DisplayPort driver will drop its
reference to the plug and attempt to continue in SOP operation.

Add new dp_state enums DP_STATE_ENTER_PRIME, DP_STATE_CONFIGURE_PRIME, and
DP_STATE_EXIT_PRIME. dp_altmode adds typec_displayport_data for the cable
plug to store the plug configuration and adds a typec_altmode reference
for the cable plug.

dp_altmode_configure takes the cable pin assignment capabilities into
account when deciding on pin configuration. dp_altmode_configure_vdm_cable
sends the configure message on SOP'.

dp_altmode_activate now attempts to enter on SOP' if applicable, and will
attempt to enter on SOP on failure.

dp_cable_altmode_vdm handles VDMs passed to the DisplayPort driver from
the tcpm.

Signed-off-by: RD Babiera <rdbabiera@google.com>
Link: https://lore.kernel.org/r/20240108191620.987785-26-rdbabiera@google.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>