viafb: add engine clock support

This patch adds support for enabling and configuring the engine on
VIAs IGPs. This is the main clock used for everything but pixel
output.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
diff --git a/drivers/video/via/hw.c b/drivers/video/via/hw.c
index df84251..e531147 100644
--- a/drivers/video/via/hw.c
+++ b/drivers/video/via/hw.c
@@ -2289,6 +2289,7 @@
 			get_sync(viafbinfo1));
 	}
 
+	clock.set_engine_pll_state(VIA_STATE_ON);
 	clock.set_primary_clock_source(VIA_CLKSRC_X1, true);
 	clock.set_secondary_clock_source(VIA_CLKSRC_X1, true);