usb: typec: tcpm/tcpci_maxim: Fix bounds check in process_rx()

usb: typec: tcpm/tcpci_maxim: Fix bounds check in process_rx()

Register read of TCPC_RX_BYTE_CNT returns the total size consisting of:

  PD message (pending read) size + 1 Byte for Frame Type (SOP*)

This is validated against the max PD message (`struct pd_message`) size
without accounting for the extra byte for the frame type. Note that the
struct pd_message does not contain a field for the frame_type. This
results in false negatives when the "PD message (pending read)" is equal
to the max PD message size.

Fixes: 6f413b559f86 ("usb: typec: tcpci_maxim: Chip level TCPC driver")
Signed-off-by: Amit Sunil Dhamne <amitsd@google.com>
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Reviewed-by: Kyle Tso <kyletso@google.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/stable/20250502-b4-new-fix-pd-rx-count-v1-1-e5711ed09b3d%40google.com
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20250502-b4-new-fix-pd-rx-count-v1-1-e5711ed09b3d@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>