gallium: Add software drm api helper to scons build

src/gallium/winsys/SConscript

@@ -17,6 +17,7 @@ if 'gdi' in env['winsys']:
 
 if env['dri']:
 	SConscript([
+		'sw/drm/SConscript',
 		'sw/dri/SConscript',
 	])
 

src/gallium/winsys/sw/drm/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_drm = env.ConvenienceLibrary(
+    target = 'ws_drm',
+    source = [
+       'sw_drm_api.c',
+    ]
+)
+Export('ws_drm')