OMAPDSS: remove dispc_irq_handler declaration

dss.h contains dispc_irq_handler declaration, even if the function is
dispc.c internal. Remove the declaration.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/omap2/dss/dss.h

@@ -398,7 +398,6 @@ void dpi_uninit_platform_driver(void) __exit;
 int dispc_init_platform_driver(void) __init;
 void dispc_uninit_platform_driver(void) __exit;
 void dispc_dump_clocks(struct seq_file *s);
-void dispc_irq_handler(void);
 
 int dispc_runtime_get(void);
 void dispc_runtime_put(void);