platform/chrome: cros_ec_typec: Poll for role swap completion

Depending on the EC USB-C stack (TCPMv2 vs PDC), EC_CMD_USB_PD_CONTROL
with a role swap request may either block until the swap completes or
queue the request asynchronously for the EC PD task and return the
current (pre-swap) role in the immediate response. On platforms where
the EC handles the swap asynchronously, checking resp.role right after
issuing the swap command sees the old role and fails with -EIO before
the USB PD handshake completes.

If the immediate response does not yet reflect the target role, poll
EC_CMD_USB_PD_CONTROL with USB_PD_CTRL_SWAP_NONE until the target role
is reached while connected, or until ROLE_SWAP_TIMEOUT_MS expires. The
timeout mirrors PD_ROLE_SWAP_TIMEOUT used by the TCPM port manager,
since a PR_Swap may legitimately take seconds when the partner answers
with Wait and the initiator retries.

While at it, report the failure modes the same way tcpm.c does, so that
userspace can tell a rejected swap from a disconnect: -ETIMEDOUT when
the partner never completes the swap, and -ENOTCONN when the port goes
away while waiting. Decoding of the swapped role is factored out into
cros_typec_resp_to_role() instead of being open coded for each swap
type, which also keeps an unhandled swap type from being misread as a
power role swap.

Fixes: ab229c2b72c3 ("platform/chrome: cros_ec_typec: Add role swap ops")
Signed-off-by: Marek Maslanka <mmaslanka@google.com>
Link: https://lore.kernel.org/r/20261007033837.708119-1-mmaslanka@google.com
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

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