First "complete" version of Intel64 support for x86. Compilation of
apps for supported boards (read: up_squared) with CONFIG_X86_LONGMODE=y
is now working. Booting, device drivers, interrupts, scheduling, etc.
appear to be functioning properly. Beware that this is ALHPA quality,
not ready for production use, but the port has advanced far enough that
it's time to start working through the test suite and samples, fleshing
out any missing features, and squashing bugs.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>