When using usb-role-switch, D+ pull-up is set as soon as DTCL_SFTDISCON is
cleared, whatever the vbus valid signal state is. The pull-up should not
be set when vbus isn't present (this is determined by the drd controller).

This patch ensures that B-Session (so Peripheral role + vbus valid signal)
is valid before clearing the DCTL_SFTDISCON bit when role switch is used.
Keep original behavior when usb-role-switch isn't used.
Acked-by: NMinas Harutyunyan <hminas@synopsys.com>
Signed-off-by: NAmelie Delaunay <amelie.delaunay@foss.st.com>
Signed-off-by: NFabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20220622160717.314580-1-fabrice.gasnier@foss.st.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>