msm: smd_debug: add support for parsing the secondary allocation table

SMD has both primary and secondary channel allocation tables where channels
can potentionally live.  The ch debugfs node only parses the primary table
which limits its usefulness in providing debugging information for issues
involving channels that exist in the secondary allocation table.

Add support to parse and output information about channels in the secondary
allocation table to assist debugging of channels that exist in that table.

Change-Id: Ib486ab05b646d03cea5e0c7db553ab30e04f8a6d
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>