Save MSACSR state. Also remove fp_status, msa_fp_status, hflags and restore
them in post_load() from the architectural registers.
Float exception flags are not present in vmstate. Information they carry
is used only by softfloat caller who translates them into MIPS FCSR.Cause,
FCSR.Flags and then they are cleared. Therefore there is no need for saving
them in vmstate.
Backports commit 644511117e7ca9f26d633a59c202a297113a796c from qemu
Reduce line wrapping throughout MSA helper macros by using a local float
status pointer rather than referring to the float status through the
environment each time. No functional change.
Backports commit 1a4d570017bf35d99340781ecb59dd3772464031 from qemu
