ARM: OMAP2+: HDQ1W: use omap_device

Convert the old-style device registration code for HDQ1W to use
omap_device.  This will allow the driver to be converted to use PM
runtime and to take advantage of the OMAP IP block management
infrastructure (hwmod, PM, etc.).

A side benefit of this conversion is that it also makes the HDQ device
available on OMAP2420.  The previous code only enabled it on 2430 and
3430.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: NeilBrown <neilb@suse.de>
Tested-by: NeilBrown <neilb@suse.de>