watchdog: hpwdt (6/12): Introduce SECS_TO_TICKS() macro

Define a macro to convert from seconds to timer ticks.

Signed-off-by: dann frazier <dannf@hp.com>
Acked-by: Thomas Mingarelli <Thomas.Mingarelli@hp.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>