intelfb: add vsync interrupt support

[02/05] intelfb: Add interrupt related register definitions

Add constants for accessing HWSTAM, IER, IIR, and IMR registers.
Add constants for interrupt types supported by the 8xx and 9xx chipsets.
The registers are also stored in the hwstate struct and dumped in the debug routine.

Signed-off-by: Eric Hustvedt <ehustvedt@cecropia.com>
diff --git a/drivers/video/intelfb/intelfb.h b/drivers/video/intelfb/intelfb.h
index e290d74..cb016fe 100644
--- a/drivers/video/intelfb/intelfb.h
+++ b/drivers/video/intelfb/intelfb.h
@@ -195,6 +195,10 @@
 	u32 mem_mode;
 	u32 fw_blc_0;
 	u32 fw_blc_1;
+	u16 hwstam;
+	u16 ier;
+	u16 iir;
+	u16 imr;
 };
 
 struct intelfb_heap_data {