msm: pil-msa: Re-organize modem pil architecture

PBLs in current and future targets parse the MBA image format on
their own. Thus, all that is required for PIL is to load the MBA
as a blob instead of interpreting the ELF headers and loading
the one "LOAD" segment.

Change-Id: I9845c7059b6782b0802c462b4133ba8df814edd3
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>
Signed-off-by: Deepak Katragadda <dkatraga@codeaurora.org>