dts: stm32: Introduce spi-bus-width property for stm32 QSPI

The spi-bus-width property provides information if the target system
has all SIO[0123] pins connected to NOR flash memory.

It must be equal to 4 to enable QSPI 4 IO operation.

Signed-off-by: Lukasz Majewski <lukma@denx.de>
1 file changed