target/mips: Extract FPU helpers to 'fpu_helper.h'

Extract FPU specific helpers from "internal.h" to "fpu_helper.h".

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20201120210844.2625602-2-f4bug@amsat.org>
diff --git a/target/mips/kvm.c b/target/mips/kvm.c
index 4776925..a5b6fe3 100644
--- a/target/mips/kvm.c
+++ b/target/mips/kvm.c
@@ -24,6 +24,7 @@
 #include "sysemu/runstate.h"
 #include "kvm_mips.h"
 #include "hw/boards.h"
+#include "fpu_helper.h"
 
 #define DEBUG_KVM 0