Add basic support for TC6393XB system features. No support for GPIO
input though.
Signed-off-by: NDmitry Baryshkov <dbaryshkov@gmail.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4702 c046a42c-6fe2-441c-8c8c-71466251a162