watchdog: designware: Convert to DM and DT probing

watchdog: designware: Convert to DM and DT probing

Convert the designware watchdog timer driver to DM and add DT probing
support. Perform minor coding style clean up, like drop superfluous
braces. These ought to be no functional change.

Signed-off-by: Marek Vasut <[email protected]>
Cc: Chin Liang See <[email protected]>
Cc: Dalon Westergreen <[email protected]>
Cc: Dinh Nguyen <[email protected]>
Cc: Jagan Teki <[email protected]>
Cc: Ley Foon Tan <[email protected]>
Cc: Philipp Tomisch <[email protected]>
Cc: Simon Goldschmidt <[email protected]>
Cc: Tien Fong Chee <[email protected]>
Reviewed-by: Jagan Teki <[email protected]>
Tested-by: Jagan Teki <[email protected]> # roc-rk3399-pc