staging: tidspbridge: remove usage of OMAP2_L4_IO_ADDRESS

Instead now use ioremap. This is needed for 3.4 since this change
emerged in mainline during one of the previous rc cycles.

These solves the following compilation breaks:

drivers/staging/tidspbridge/core/tiomap3430.c:
    In function ‘bridge_brd_start’:
drivers/staging/tidspbridge/core/tiomap3430.c:425:4:
    error: implicit declaration of function ‘OMAP2_L4_IO_ADDRESS’

drivers/staging/tidspbridge/core/wdt.c: In function ‘dsp_wdt_init’:
drivers/staging/tidspbridge/core/wdt.c:56:2:
    error: implicit declaration of function ‘OMAP2_L4_IO_ADDRESS’

For control registers a new function needs to be defined so we
can get rid of a layer violation, but that approach must be queued
for the next merge window.

As seen in:
http://www.arm.linux.org.uk/developer/build/


platform: omap4430-sdp		build: uImage
config: randconfig			version: 3.4.0-rc3
start time: Apr 20 2012 01:07

Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Omar Ramirez Luna <omar.ramirez@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>