ARM: dts: msm: Modify mem timer interrupt on sdm855

Update interrupt number information for mem timer
on sdm855 SoC. This timer is in always on domain
and can be used to wake up cores from low power modes.

Change-Id: Id57679c531b7d2e8fb0d45bc7076903b00fd8b85
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>