HDQ driver update

This patch updates the HDQ driver not to export omap_hdq_get, omap_hdq_put
and omap_hdq_break fns,use them internally in the driver.Remove the unused
function omap_hdq_reset.

Signed-off-by: Madhusudhan Chikkature<madhu.cr@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>