watchdog: sunxi: support parameterized compatible strings

This patch adds support for hardware parameters tied to compatible
strings, so similar hardware can reuse the driver.

This will be used to support the newer watchdog found in A31 and
later SoCs. Differences in the new hardware include separate
interrupt lines for each watchdog, and corresponding interrupt
control/status registers. Watchdog control registers were also
slightly rearranged.

Also replace iowrite32 with writel in various places changed.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
watchdog: sunxi: Add A31 watchdog support

This patch adds support for the watchdog hardware found in A31 and
newer SoCs. This new hardware has registers at different offsets, and
the system reset control has been split out of the "mode" register
into a new "configuration" register.

Differences not supported by this driver include separate interrupt
lines for each watchdog, instead of sharing an interrupt line and
registers with the timer block.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>