msm: sps: add support for register mapping

BAM HW has different internal register offsets for different
chipset families. Different chipsets in different chipset families
are allowed to use the same defconfig file now. Thus, add the
support in the driver for intenal register offset mapping.

Change-Id: I3c5b7a81c805330f461bdfc47f1f9c18d75c58fa
Signed-off-by: Yan He <yanhe@codeaurora.org>