ARM: dts: DRA7: Enable Timers 13 through 16

The Timers 13 through 16 have been added previously in
disabled state. These timers are common timers that are
present on all DRA7 family of SoCs, so enable these
devices by default like the rest of the DMTimers.

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