mfd: omap-usb-host: get rid of cpu_is_omap..() macros

Instead of using cpu_is_omap..() macros in the device driver we
rely on information provided in the platform data.

The only information we need is whether the USB Host module has
a single ULPI bypass control bit for all ports or individual bypass
control bits for each port. OMAP3 REV2.1 and earlier have the former.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
[tony@atomide.com: updated to remove plat/cpu.h]
Signed-off-by: Tony Lindgren <tony@atomide.com>