st/wgl: include u_debug.h

To get declaration for debug_printf() directly instead of getting it
indirectly through os_thread.h

Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Reviewed-by: Charmaine Lee <charmainel@vmware.com>

src/gallium/state_trackers/wgl/stw_ext_context.c

@@ -35,6 +35,8 @@
 #include "stw_device.h"
 #include "stw_ext_context.h"
 
+#include "util/u_debug.h"
+
 
 wglCreateContext_t wglCreateContext_func = 0;
 wglDeleteContext_t wglDeleteContext_func = 0;

src/gallium/state_trackers/wgl/stw_ext_pbuffer.c

@@ -35,6 +35,8 @@
 #include "pipe/p_defines.h"
 #include "pipe/p_screen.h"
 
+#include "util/u_debug.h"
+
 #include "stw_device.h"
 #include "stw_pixelformat.h"
 #include "stw_framebuffer.h"

src/gallium/state_trackers/wgl/stw_getprocaddress.c

@@ -37,6 +37,8 @@
 #include "stw_icd.h"
 #include "stw_nopfuncs.h"
 
+#include "util/u_debug.h"
+
 struct stw_extension_entry
 {
    const char *name;