QCamera2: Retreive stats debug data from previous valid frame

If the stats debug data sent from MCT is valid, then store
a copy in HAL. If during snapshot, the current frame's debug
data is not valid, then the most recent valid data which was
saved is used

Change-Id: I7f4097085d3220abe105f0a59ffbfc5c44227467
Merge "QCamera2: Retreive stats debug data from previous valid frame"
Merge 28f84f42a7d72bf28b482107bafb9f6f6f40b76a on remote branch

Change-Id: I985f1c1139d3495aa4997946e9a287f6f1d314a3
QCamera2: Remove semaphore used for parm buf synchronization.

CAM_PRIV_PARM IOCTL call will be blocking in HAL till the
parameters are copied and processed in backend. So, no need
to have a semaphore to do synchronization again.

Change-Id: I598e3f40a73085d6893532a4416b93035cf52f92
Merge "QCamera2: Remove semaphore used for parm buf synchronization."
Merge 4aa5b2808e043f84e65af87001a843d88612c872 on remote branch

Change-Id: Ifebea01c0fb8fa191544de23cf3aff6e83fa1150
Merge "Merge 4aa5b2808e043f84e65af87001a843d88612c872 on remote branch"