watchdog/denali: Adding DesignWare watchdog driver support

To add the DesignWare watchdog driver support. It required
information such as register base address and clock info from
configuration header file  within include/configs folder.

Signed-off-by: Chin Liang See <clsee@altera.com>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Heiko Schocher <hs@denx.de>
Cc: Tom Rini <trini@ti.com>