arm: dts: mdm9630: Firmware memory dump region

Adding subsystem restart support for WLAN PCIe module so that it
has the mechanism to recover from firmware fatal errors and it
also collects the RAM dump. This change adds the memory region
starting address and size required for collecting the RAM dump.

Change-Id: I9a08e904e12c64fe09d63ae2a96d303ed01bc0a7
Signed-off-by: Prashanth Bhatta <bhattap@codeaurora.org>