target/mips: Move IEEE rounding mode array to new source file

target/mips: Move IEEE rounding mode array to new source file

restore_msa_fp_status() is declared inlined in fpu_helper.h,
and uses the ieee_rm[] array. Therefore any code calling
restore_msa_fp_status() must have access to this ieee_rm[] array.

kvm_mips_get_fpu_registers(), which is in target/mips/kvm.c,
calls restore_msa_fp_status.

Except this tiny array, the rest of fpu_helper.c is only useful
for the TCG accelerator.

To be able to restrict fpu_helper.c to TCG, we need to move the
ieee_rm[] array to a new source file.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210428170410.479308-3-f4bug@amsat.org>