MIPS: Export MSA functions used by lose_fpu(1) for KVM

Export the _save_msa asm function used by the lose_fpu(1) macro to GPL
modules so that KVM can make use of it when it is built as a module.

This fixes the following build error when CONFIG_KVM=m and
CONFIG_CPU_HAS_MSA=y due to commit f798217d ("KVM: MIPS: Don't leak
FPU/DSP to guest"):

ERROR: "_save_msa" [arch/mips/kvm/kvm.ko] undefined!

Fixes: f798217d (KVM: MIPS: Don't leak FPU/DSP to guest)
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.15+
Patchwork: https://patchwork.linux-mips.org/patch/9261/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/mips_ksyms.c

@@ -15,6 +15,7 @@
 #include <asm/uaccess.h>
 #include <asm/ftrace.h>
 #include <asm/fpu.h>
+#include <asm/msa.h>
 
 extern void *__bzero(void *__s, size_t __count);
 extern long __strncpy_from_kernel_nocheck_asm(char *__to,
@@ -36,6 +37,9 @@ extern long __strnlen_user_asm(const char *s);
  * Core architecture code
  */
 EXPORT_SYMBOL_GPL(_save_fp);
+#ifdef CONFIG_CPU_HAS_MSA
+EXPORT_SYMBOL_GPL(_save_msa);
+#endif
 
 /*
  * String functions