target/loongarch/meson: move gdbstub.c to loongarch.ss

gdbstub.c is not specific to TCG and can be used by
other accelerators, such as KVM accelerator

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Song Gao <gaosong@loongson.cn>
Message-Id: <20240102020200.3462097-1-gaosong@loongson.cn>

target/loongarch/meson.build

@@ -3,14 +3,14 @@ gen = decodetree.process('insns.decode')
 loongarch_ss = ss.source_set()
 loongarch_ss.add(files(
   'cpu.c',
+  'gdbstub.c',
 ))
 loongarch_tcg_ss = ss.source_set()
 loongarch_tcg_ss.add(gen)
 loongarch_tcg_ss.add(files(
   'fpu_helper.c',
   'op_helper.c',
   'translate.c',
-  'gdbstub.c',
   'vec_helper.c',
 ))
 loongarch_tcg_ss.add(zlib)