ARM: dts: omap5-uevm: Add watchdog timers for IPU and DSP

The watchdog timers have been added for the IPU and DSP remoteproc
devices for the OMAP5 uEVM board. The following timers (same as the
timers on OMAP4 Panda boards) are used as the watchdog timers,
        DSP : GPT6
        IPU : GPT9 & GPT11 (one for each Cortex-M4 core)

The MPU-side drivers will use this data to initialize the watchdog
timers, and listen for any watchdog triggers. The BIOS-side code
needs to configure and refresh these timers properly to not throw
a watchdog error.

These timers can be changed or removed as per the system integration
needs, alongside appropriate equivalent changes on the firmware side.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>