watchdog: rzg2l_wdt: Handle TYPE-B reset for RZ/V2M

As per section 48.4 of the HW User Manual, IPs in the RZ/V2M
SoC need either a TYPE-A reset sequence or a TYPE-B reset
sequence. More specifically, the watchdog IP needs a TYPE-B
reset sequence.

If the proper reset sequence isn't implemented, then resetting
IPs may lead to undesired behaviour. In the restart callback of
the watchdog driver the reset has basically no effect on the
desired funcionality, as the register writes following the reset
happen before the IP manages to come out of reset.

Implement the TYPE-B reset sequence in the watchdog driver to
address the issues with the restart callback on RZ/V2M.

Fixes: ec122fd9 ("watchdog: rzg2l_wdt: Add rzv2m support")
Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20221117114907.138583-3-fabrizio.castro.jz@renesas.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>