Do not use -msynci flag for Xburst 4780 cores

synci does not provide coherency between CPU's on this device

Change-Id: I10e73fa49859e55d018884c6682b5a00b887e0a1
Signed-off-by: Chris Dearman <chris.dearman@imgtec.com>
Merge "Do not use -msynci flag for Xburst 4780 cores"
Merge https://android.googlesource.com/platform/build into jb-devel