qseecom: Add support for scaling bus

Add bus scaling request for four various levels:
LOW, MEDIUM, HIGH and INACTIVE.  Expose IOCTLs to user
space QSEECOMAPI  library to request for specific
bandwidth needs.

Change-Id: Iab58d1ce5e91d9a1a72b6b0d3e1f97ae1bd1ca94
Signed-off-by: Mona Hossain <mhossain@codeaurora.org>
Signed-off-by: Zhen Kong <zkong@codeaurora.org>