usb: dwc2: host: set active bit in isochronous descriptors

Active bit must be enabled in all scheduled descriptors. Else transfer
never start.
Remove previous code which was not correctly configuring descriptors.
Active bit was set before calling dwc2_fill_host_isoc_dma_desc() which
is erasing dma_desc->status.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>