msm: sps: improve debugging in SPS driver

1> Output BAM_TEST_BUS content with specified TEST_BUS_SEL value,
which helps HW team's debugging.
2> Support selection of pipes to only output registers' values of
selected pipes.

Change-Id: Ic2e0cb6bd3b0300baa9f96dcdd62069c7ae80c36
Signed-off-by: Yan He <yanhe@codeaurora.org>
4 files changed