usb: musb: am335x: fix pdev resource bug

We are overwriting the resource->name to "mc" so that musb_core.c
can understand it but this is also changing the platform device's
resource->name as the "name" address remains same.

Fixing the same by changing the resource->name field of local
structure only.

Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>