libobs-opengl: Make some includes unconditional

Move 3 headers out from the Linux-specific section.
Without these headers functions like open, close, drmXx aren't found.

* open requires <fcntl.h>
* close requres <unistd.h>
* drmXx requires <xf86drm.h>

libobs-opengl/gl-egl-common.c

@@ -17,8 +17,11 @@
 
 #include "gl-egl-common.h"
 
+#include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
+#include <xf86drm.h>
 
 #include <glad/glad_egl.h>
 
@@ -26,9 +29,6 @@
 
 #include <linux/types.h>
 #include <asm/ioctl.h>
-#include <xf86drm.h>
-#include <unistd.h>
-#include <fcntl.h>
 typedef unsigned int drm_handle_t;
 
 #else