omap: Don't use hw_error() in device init() methods

Device init() methods aren't supposed to call hw_error(), they should
report the error and fail cleanly.  Do that.

The errors are all device misconfiguration.  All callers use
qdev_init_nofail(), so this patch merely converts hw_error() crashes
into &error_abort crashes.  Improvement, because now it crashes closer
to where the misconfiguration bug would be, and a few more bad
examples of hw_error() use are gone.

Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <1450370121-5768-3-git-send-email-armbru@redhat.com>
