kernel: fix portability issues of the x86 vdso2c utility

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 44757

target/linux/generic/patches-3.18/213-x86_vdso_portability.patch

@@ -0,0 +1,13 @@
+--- a/arch/x86/vdso/vdso2c.c
++++ b/arch/x86/vdso/vdso2c.c
+@@ -63,8 +63,8 @@
+ 
+ #include <tools/le_byteshift.h>
+ 
+-#include <linux/elf.h>
+-#include <linux/types.h>
++#include <elf.h>
++#include <stdbool.h>
+ 
+ const char *outfilename;
+