headers_check fix: x86, sigcontext.h

fix the following 'make headers_check' warnings:

  usr/include/asm/sigcontext.h:5: include of <linux/types.h> is preferred over <asm/types.h>
  usr/include/asm/sigcontext.h:24: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

arch/x86/include/asm/sigcontext.h

@@ -2,7 +2,7 @@
 #define _ASM_X86_SIGCONTEXT_H
 
 #include <linux/compiler.h>
-#include <asm/types.h>
+#include <linux/types.h>
 
 #define FP_XSTATE_MAGIC1	0x46505853U
 #define FP_XSTATE_MAGIC2	0x46505845U