ANDROID: x86: disable CFI for do_syscall_*

x86 doesn't use syscall wrappers in 4.14, which means do_syscall_*
function end up making an indirect call using a mismatching function
pointer. Disable CFI to work around the type mismatch.

Bug: 145297900
Change-Id: I91dd2bd94f9b5174c03cc3d3a1007061f7fe332e
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>