msm: pm: debug counters to DDR

Today the PC debug counters are placed in IMEM. There is
a need for more memory to save these counters for extra
CPUs in newer platforms. As IMEM is scarce resource, move
these per CPU counters to non cacheable area in DDR.
Also save the physical start address in IMEM for easy
access to location of counters while analyzing dumps.

Change-Id: I049a67594d6a7b292c7fe617396639efa46c8d96
Signed-off-by: Venkat Devarasetty <vdevaras@codeaurora.org>