OMAPDSS: HDMI: OMAP4: Update IRQ flags for the HPD IRQ request

genirq requires that the IRQ requests that do not provided a handler to
use the IRQF_ONESHOT flag. This is to prevent situations in which the irq line
is reenabled while the interrupt is still asserted. While this situation may
not happen in edge type interrupts, genirq still requires to use IRQF_ONESHOT.

Also, remove the IRQF_DISABLED as the flag is now a NOOP and has been
deprecated.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>