drm/bridge: analogix_dp: fix no drm hpd event when panel plug in

The enum value of DP_IRQ_TYPE_HP_CABLE_IN is zero, but driver only
send drm hp event when the irq_type and the enum value is true.

if (irq_type & DP_IRQ_TYPE_HP_CABLE_IN || ...)
	drm_helper_hpd_irq_event(dp->drm_dev);

So there would no drm hpd event when cable plug in, to fix that
just need to assign all hotplug enum with no-zero values.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Yakir Yang <ykk@rock-chips.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
Reviewed-by: Tomasz Figa <tomasz.figa@chromium.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>