Add nano syntax highlighting definitions

RescueOS v1.1 included syntax highlighting definitions for nano.  Patch
buildroot's nano package to have it install these files from nano's
source.

buildroot-patches/series

@@ -1,3 +1,4 @@
 gcc46-avoid-segfault.patch
 linux-firmware-version-bump.patch
 linux-firmware-wl1251.patch
+nano-add-syntax-highlighting.patch