ARM: dts: msm: Update the timer frequency for SDM845 RUMI

Timer frequency of 1Mhz results into issues where kernel is alwasy busy
in hanling the timer interrupts. Due to this s/w watchdog timeouts
and ANRs are seen when we boot Android. Revert back to 19.2Mhz for timer
frequency.

Change-Id: I4aafc39cae6c48752135544b7e640981be939d45
Signed-off-by: Channagoud Kadabi <ckadabi@codeaurora.org>