Davinci: iotable based ioremap() interception

This patch allows for a more flexible ioremap() interception based on iotable
contents.

With this patch, the ioremap() interception code can properly translate
addresses only after davinci_soc_info has been initialized.  Consequently,
in soc-specific init functions, davinci_common_init() has to happen before any
ioremap() attempts. The da8xx init sequence has been suitably modified to meet
this restriction.

Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>