usb: atmel_usba_udc: fix it to deal with final dma channel
usb: atmel_usba_udc: fix it to deal with final dma channel

As, the interrupt for DMA is counted from 1, so need to checked
the USBA_NR_DMAS, in old way, it only check (USBA_NR_DMAS - 1),
so fix it.

Reported-by: Max Liao <1b7bd29ecdd00558987aa598802ace0c3e192690@embest-tech.com>
Signed-off-by: Bo Shen <b3e6a3251704a94eee1cf08e0adc382e6cb535ee@atmel.com>
Signed-off-by: Felipe Balbi <94dddeeef08b001e003cce128ddc162a4e2c6cd2@ti.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs