msm: smd: separate pil attributes from subsystem name

All remote subsystems have a name, but not all remote subsystems are
loadable by PIL.  Storing a single value to be used as both the name and to
indicate a subsystem can be loaded by PIL is limiting in cases where a
subsystem cannot be loaded by PIL.  In such cases, workarounds are
necessary, or useful functionality is broken.

In addition to listing a name for a subsystem, indicate if it can be loaded
by PIL which eliminates limitations when loading by PILL may not apply.

Change-Id: Id7b6ee028ac6b1ecdc12a4fd4aeebf51cb45a1a0
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>