xtensa, kernel/sched: Move next switch_handle selection to the scheduler

The xtensa asm2 layer had a function to select the next switch handle
to return into following an exception.  There is no arch-specific code
there, it's just scheduler logic.  Move it to the scheduler where it
belongs.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
3 files changed