MIPS: lib: Mark intrinsics notrace

On certain MIPS32 devices, the ftrace tracer "function_graph" uses
__lshrdi3() during the capturing of trace data. ftrace then attempts to
trace __lshrdi3() which leads to infinite recursion and a stack overflow.
Fix this by marking __lshrdi3() as notrace. Mark the other compiler
intrinsics as notrace in case the compiler decides to use them in the
ftrace path.

Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
Cc: <linux-mips@linux-mips.org>
Cc: <linux-kernel@vger.kernel.org>
Cc: <stable@vger.kernel.org> # 4.2.x-
Patchwork: https://patchwork.linux-mips.org/patch/13354/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/lib/bswapsi.c

@@ -1,6 +1,6 @@
 #include <linux/module.h>
 
-unsigned int __bswapsi2(unsigned int u)
+unsigned int notrace __bswapsi2(unsigned int u)
 {
 	return (((u) & 0xff000000) >> 24) |
 	       (((u) & 0x00ff0000) >>  8) |