linux-fsl-sdk-v1.5: Fix buffer overwrite issue in fsl espi

When the fsl espi driver is enabled, it has probability to cause
kernel exception.  In Accton AS6700_32X, we inject broadcast
packets into the management port steadily, the exception will
happen after user inputs the 'reboot' command to the kernel.

Ref:
- http://www.spinics.net/lists/linux-spi/msg01076.html

Signed-off-by: Curt Brune <curt@cumulusnetworks.com>
Accton AS6700_32X: Add to support ONIE

Signed-off-by: Curt Brune <curt@cumulusnetworks.com>