target/xtensa: drop num_[core_]regs from dc232b/dc233c configs

Now that xtensa_count_regs does the right thing, remove manual
initialization of these fields from the affected configurations and let
xtensa_finalize_config initialize them. Add XTREG_END to terminate
register lists.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
4 files changed