usb: ehci: tegra: Fix Slab corruption error

Give ownership of the DMA buffer back to the processor first and
then free the buffer. Otherwise processor won't be able to
access the dma mapped buffers and this would lead to slab
corruption.
When the DMA buffer is freed without a call to dma_sync_single_for_cpu(),
the kernel won't be able to set the buffer as POISON FREE and when we
acquire this memory back again the kernel will start printing slab
corruption output as the memory is not set to POISON FREE

Bug 1017884
Bug 1018161
Reviewed-on: http://git-master/r/#change,122151
Signed-off-by: Preetham Chandru R <pchandru@nvidia.com>

Change-Id: I00d6cb185cd2314cccb56f968eb0a05288588c13
Reviewed-on: http://git-master/r/122390
Reviewed-by: Simone Willett <swillett@nvidia.com>
Tested-by: Simone Willett <swillett@nvidia.com>
usb: gadget: fix otg hang with uboot

zombah reported on IRC that irq trigger on rising edge instead of
high level fixes booting with uboot and build-in otg driver.

Signed-off-by: Marc Dietrich <marvin24@gmx.de>