usb: misc: usb3503: refactor code to prepare for usb3803 addition

usb: misc: usb3503: refactor code to prepare for usb3803 addition

Refactor code to simplify adding support for USB3803 and bypass mode.

Remove static usb3503_reset() and move it to usb3503_switch_mode(),
with the addition of the bypass mode we need to drive the various
control signals to the expected configuration, not just to
assert/release the reset.

In addition to that the usb3503_connect() needs to be called only
for HUB mode.

No functional changes expected nor intended because of this change.

Signed-off-by: Emanuele Ghidoli <emanuele.ghidoli@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Link: https://lore.kernel.org/r/20230313165039.255579-3-francesco@dolcini.it
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>