gallium: Add pipe wrapper software winsys to scons build

src/gallium/winsys/SConscript

@@ -1,5 +1,10 @@
 Import('*')
 
+
+SConscript([
+	'sw/wrapper/SConscript',
+])
+
 if 'xlib' in env['winsys']:
 	SConscript([
 		'sw/xlib/SConscript',

src/gallium/winsys/sw/wrapper/SConscript

@@ -0,0 +1,21 @@
+#######################################################################
+# SConscript for xlib winsys
+
+
+Import('*')
+
+env = env.Clone()
+
+env.Append(CPPPATH = [
+    '#/src/gallium/include',
+    '#/src/gallium/auxiliary',
+    '#/src/gallium/drivers',
+])
+
+ws_wrapper = env.ConvenienceLibrary(
+    target = 'ws_wrapper',
+    source = [
+       'wrapper_sw_winsys.c',
+    ]
+)
+Export('ws_wrapper')