arm: mvebu: turris_mox: Fix unstable board topology reading

arm: mvebu: turris_mox: Fix unstable board topology reading

The pre-relocation board topology reading in board_fix_fdt() is
unstable: sometimes wrong data are read from the SPI bus.

This is due to wrong order of SPI bus configuration instructions: we
first need to set the pins to SPI mode, and only after that configure
the bus.

Also add a 1ms delay before enabling chip-select, so that the clock pin
is high for some time before reading the bus.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>