libinput: Add missing header to fix compilation

Signed-off-by: Rosen Penev <rosenp@gmail.com>

libs/libinput/Makefile

@@ -6,7 +6,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=libinput
 PKG_VERSION:=1.7.3
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=http://www.freedesktop.org/software/libinput/

libs/libinput/patches/010-musl-fix.patch

@@ -0,0 +1,10 @@
+--- a/src/libinput.h
++++ b/src/libinput.h
+@@ -29,6 +29,7 @@
+ extern "C" {
+ #endif
+ 
++#include <stdarg.h>
+ #include <stdlib.h>
+ #include <stdint.h>
+ #include <libudev.h>