target/i386: fix avx2 instructions vzeroall and vpermdq

vzeroall: xmm_regs should be used instead of xmm_t0
vpermdq: bit 3 and 7 of imm should be considered

Signed-off-by: Xinyu Li <lixinyu20s@ict.ac.cn>
Message-Id: <20230510145222.586487-1-lixinyu20s@ict.ac.cn>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>