target/xtensa: use tcg_constant_* for remaining opcodes

target/xtensa: use tcg_constant_* for remaining opcodes

- gen_jumpi passes target PC to the helper;
- gen_callw_slot uses callinc (1..3);
- gen_brcondi passes immediate field (less than 32 different possible
  values) to the helper;
- disas_xtensa_insn passes PC to the helpers;
- translate_entry passes PC, stack register number (0..15) and stack
  frame size to the helper;
- gen_check_exclusive passes PC and boolean flag to the helper;
- test_exceptions_retw passes PC to the helper;
- gen_check_atomctl passes PC to the helper;
- translate_ssai passes immediate shift amount (0..31) to the helper;
- gen_waiti passes next PC and an immediate (0..15) to the helper;

use tcg_constant_* for the constants listed above. Fold gen_waiti body
into the translate_waiti as it's the only user.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>