InOsEmuPkg: Implement gIdleLoopEventGuid.

InOsEmuPkg: Implement gIdleLoopEventGuid.

Added a CpuSleep () API to the Emulator Thunk. We needed to do this as the Stall() works hard to not get broken by the timer tic (POSIX signal). nanosleep() gets interrupted by the timer signal so it is a good emulator of a CpuSleep(); I was also able to remove some stalls in the X11 keyboard and mouse checking events, now that the gIdleLoopEventGuid was added.

Signed-off-by: andrewfish
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@11846 6f19259b-4bc3-4df7-8a09-765794883524