This add support for kernel 4.9 to the ar71xx target.
It was compile tested with the generic, NAND and mikrotik subtarget.
Multiple members of the community tested it on their boards and did not
report any major problem so far.
Especially the NAND part received some changes to adapt to the new
kernel APIs. The serial driver hack used for the Arduino Yun was not
ported because the kernel changed there a lot.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Commit af79fdbe4a changed the code to use tx_nbits for dual SPI tx
transfers, however the SPI stack only allows this when the device mode
includes the relevant bit as well
Signed-off-by: Felix Fietkau <nbd@nbd.name>