msm: msm_bus: Allow QOS address offset to be configurable

Currently the QOS base address for NOC is assumed to be at an
offset of 0x3000 from the base address of the NOC device. But this is not
the case in some chipsets. Make the QOS address offset a configurable
platform parameter.

Change-Id: If0adb8839b525c3ede0f5a61a65fd27826834377
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>