diag: Modify diag to support multiple hsic instances

The debugfs implementation and diag code interfacing with the
diag userspace library currently only supports one instance
of diag bridge using hsic.  Make changes to support multiple
instances of diag bridge using hsic.

Change-Id: I073354140fa0854b3aa0f3782c98597abb78324c
Signed-off-by: Dixon Peterson <dixonp@codeaurora.org>
6 files changed