mcast-tools: fix linux/pim.h include

fix wrong struct in pim.h big endian case
it leads to compile error on ar71xx and other arch
Error was:
In file included from debug.c:71:0:
../include/linux/pim.h:14:3: error: expected specifier-qualifier-list before 'pim_type'
   pim_type:4;  /* PIM message type */
   ^
make[6]: *** [debug.o] Error 1

Signed-off-by: Dirk Neukirchen <dirkneukirchen@web.de>

mcast-tools/patches/0004-fix_linux_pim.h_include.patch

@@ -0,0 +1,11 @@
+--- a/include/linux/pim.h
++++ b/include/linux/pim.h
+@@ -10,7 +10,7 @@ struct pim {
+ 	__u8	pim_type:4,		/* PIM message type */
+ 		pim_ver:4;		/* PIM version */
+ #elif defined(__BIG_ENDIAN_BITFIELD)
+-	__u8	pim_ver:4;		/* PIM version */
++	__u8	pim_ver:4,		/* PIM version */
+ 		pim_type:4;		/* PIM message type */
+ #endif
+ 	__u8	pim_rsv;		/* Reserved */