Fixed the clipping for the postscript driver and turned it on (by setting
PSDRV_SetDeviceClipping in the function table).

diff --git a/graphics/psdrv/init.c b/graphics/psdrv/init.c
index 4b8c138..f7d104d 100644
--- a/graphics/psdrv/init.c
+++ b/graphics/psdrv/init.c
@@ -78,7 +78,7 @@
     NULL,                            /* pSelectPalette */
     PSDRV_SetBkColor,                /* pSetBkColor */
     NULL,                            /* pSetBkMode */
-    NULL,                            /* pSetDeviceClipping */
+    PSDRV_SetDeviceClipping,         /* pSetDeviceClipping */
     NULL,                            /* pSetDIBitsToDevice */
     NULL,                            /* pSetMapMode (optional) */
     NULL,                            /* pSetMapperFlags */