Xtensa fixes for 3.14:
- allow booting xtfpga on boards with new uBoot and >128MBytes memory;
- drop nonexistent GPIO32 support from fsf variant;
- don't select USE_GENERIC_SMP_HELPERS;
- enable common clock framework support, set up ethoc clock on xtfpga;
- wire up sched_setattr and sched_getattr syscalls.
Signed-off-by: Chris Zankel <chris@zankel.net>