staging: fsl-dpaa2/eth: Fix DMA mapping direction

staging: fsl-dpaa2/eth: Fix DMA mapping direction

BugLink: https://bugs.launchpad.net/bugs/1836117
[ Upstream commit 466bcdc1fa303be175c45d054bb00effc575033a ]

We are using DMA_FROM_DEVICE when mapping RX frame buffers,
but DMA_BIDIRECTIONAL for unmap. Fix the direction for DMA
unmapping operation.

Fixes: 87eb55e418b7 ("staging: fsl-dpaa2/eth: Fix potential endless loop")
Signed-off-by: Ioana Radulescu <ruxandra.radulescu@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>