target/riscv: rvv-1.0: remove rvv related codes from fcsr registers

target/riscv: rvv-1.0: remove rvv related codes from fcsr registers

* Remove VXRM and VXSAT fields from FCSR register as they are only
  presented in VCSR register.
* Remove RVV loose check in fs() predicate function.

Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20211210075704.23951-9-frank.chang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>