usb: typec: tcpm: Refactor tcpm_handle_vdm_request payload handling

Refactor the tcpm_handle_vdm_request payload handling by doing the
endianness conversion only once directly inside tcpm_handle_vdm_request
itself instead of doing it multiple times inside various helper functions
called by tcpm_handle_vdm_request.

This is a preparation patch for some further refactoring to fix an AB BA
lock inversion between the tcpm code and some altmode drivers.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20200724174702.61754-3-hdegoede@redhat.com


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