[Buildroot] [PATCH] lua: add patch to fix pkg-config file for version 5.1.x

[Jörg Krause]

This patch applies the fix added in commit
8d845683e37640d33c186c0091ccce6ae3ef0777 to Lua version 5.1.x.

When Lua is linked with additional libraries, these libraries should go
into the pkg-config file as well.

Otherwise, linking swupdate with the lua library (version 5.1.x) fails:

```
/home/buildroot/output/host/arm-buildroot-linux-gnueabihf/sysroot/usr/lib/liblua.so: undefined reference to `dlopen'
/home/buildroot/output/host/arm-buildroot-linux-gnueabihf/sysroot/usr/lib/liblua.so: undefined reference to `dlclose'
/home/buildroot/output/host/arm-buildroot-linux-gnueabihf/sysroot/usr/lib/liblua.so: undefined reference to `dlerror'
/home/buildroot/output/host/arm-buildroot-linux-gnueabihf/sysroot/usr/lib/liblua.so: undefined reference to `dlsym'
```

The build error was detected when building the package swupdate from
upstream with Lua 5.1 compatibility support [1] enabled.

[1] https://groups.google.com/forum/#!topic/swupdate/cBvq27-zuvs

Signed-off-by: Jörg Krause <joerg.krause at embedded.rocks>
---
 package/lua/5.1.5/0003-add-MYLIBS-to-Libs-in-lua-pc.patch | 12 ++++++++++++
 1 file changed, 12 insertions(+)
 create mode 100644 package/lua/5.1.5/0003-add-MYLIBS-to-Libs-in-lua-pc.patch

diff --git a/package/lua/5.1.5/0003-add-MYLIBS-to-Libs-in-lua-pc.patch b/package/lua/5.1.5/0003-add-MYLIBS-to-Libs-in-lua-pc.patch
new file mode 100644
index 0000000000..8a5a0d85be
--- /dev/null
+++ b/package/lua/5.1.5/0003-add-MYLIBS-to-Libs-in-lua-pc.patch
@@ -0,0 +1,12 @@
+diff -purN lua-5.1.5.orig/etc/lua.pc lua-5.1.5/etc/lua.pc
+--- lua-5.1.5.orig/etc/lua.pc	2017-10-12 09:25:20.339277165 +0200
++++ lua-5.1.5/etc/lua.pc	2017-10-12 09:26:37.272796305 +0200
+@@ -25,7 +25,7 @@ Name: Lua
+ Description: An Extensible Extension Language
+ Version: ${R}
+ Requires: 
+-Libs: -L${libdir} -llua -lm
++Libs: -L${libdir} -llua -lm @MYLIBS@
+ Cflags: -I${includedir}
+ 
+ # (end of lua.pc)
-- 
2.14.2