arm64: dts: mt7622: declare SPI-NAND present on BPI-R64

arm64: dts: mt7622: declare SPI-NAND present on BPI-R64

The SPI-NOR node in the device tree of the BananaPi R64 has most likely
been copied from the reference board's device tree even though the R64
comes with an SPI-NAND chip rather than SPI-NOR.

Setup the Serial NAND Flash Interface (SNFI) controller, enable
hardware BCH error detection and correction engine and add the SPI-NAND
chip including basic partitions,

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://lore.kernel.org/r/ZEA96dmaXqTpk8u8@makrotopia.org
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>