bus: ti-sysc: Fix watchdog quirk handling

I noticed that when probed with ti-sysc, watchdog can trigger on am3, am4
and dra7 causing a device reset.

Turns out I made several mistakes implementing the watchdog quirk handling:

1. We must do both writes to spr register

2. We must also call the reset quirk on disable

3. On am3 and am4 we need to also set swsup quirk flag

I probably only tested this earlier with watchdog service running when the
watchdog never gets disabled.

Fixes: 4e23be47

 ("bus: ti-sysc: Add support for module specific reset quirks")
Signed-off-by: Tony Lindgren <tony@atomide.com>