host/include/loongarch64: Fix inline assembly compatibility with Clang

host/include/loongarch64: Fix inline assembly compatibility with Clang

Clang on LoongArch only accepts fp register names in the dollar-prefixed
form, while GCC allows omitting the dollar. Change registers in ASM
clobbers to the dollar-prefixed form to make user emulators buildable
with Clang on loongarch64. No functional change invovled.

Cc: qemu-stable@nongnu.org
Fixes: adc8467e697 ("host/include/loongarch64: Add atomic16 load and store")
Signed-off-by: Yao Zi <ziyao@disroot.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Bibo Mao <maobibo@loongson.cn>