USB: musb: Kill board specific pinmux from driver file

This pin-muxing is best done in the board files. The driver should
not do this explicitly.

Also, this code causes a warning to be thrown when OMAP2430 and OMAP3/4
support are enabled in the same kernel.

Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Acked-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>