[XTENSA] Prevent inlining ISS platform asm constructs

The simcall asm macro assumes Windowed ABI parameter passing
in registers, and doesn't work if its containing function gets
inlined.  This fix prevents that from happening.
Signed-off-by: Marc Gauthier <marc@tensilica.com>

arch/xtensa/platforms/iss/console.c

@@ -43,6 +43,7 @@ static DEFINE_SPINLOCK(timer_lock);
 
 int errno;
 
+static int __simc (int a, int b, int c, int d, int e, int f) __attribute__((__noinline__));
 static int __simc (int a, int b, int c, int d, int e, int f)
 {
 	int ret;

arch/xtensa/platforms/iss/network.c

@@ -107,6 +107,7 @@ struct iss_net_private {
 
 static int errno;
 
+static int __simc (int a, int b, int c, int d, int e, int f) __attribute__((__noinline__));
 static int __simc (int a, int b, int c, int d, int e, int f)
 {
 	int ret;