octeontx: fix mcp251x can controller

octeontx: fix mcp251x can controller

Update the can-mcp251x-convert-to-half-duplex-SPI patch to fix reception

Some SPI host controllers such as the Cavium Thunder TX do not support
full-duplex SPI. Using half-duplex transfers allows the driver to work
with those host controllers.

This patch fixes the fact that mcp251x_hw_rx_frame was still relying on
a full-duplex transfer where bits were being shifted on MOSI at the same time
as MISO. After splitting the transaction into a spi_write_then_read() care
must be taken to ignore the first byte.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>