ARM: SAMSUNG: Let platforms use the new watchdog reset driver

This patch moves all platforms using the legacy watchdog reset helper
function to the new watchdog reset driver.

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Tested-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>