usb: musb: Use normal module_init for 2430 glue

There's no longer any need for custom initcall level for
musb.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>