board: st: stm32mp1: use of correct compatible string to add partitions

board: st: stm32mp1: use of correct compatible string to add partitions

Current compatible string used to update SPI NAND and SPI NOR devices
can lead to a wrong partitions update (for example, SPI NAND partitions
added to SPI NOR node in the device tree). To avoid this wrong behavior,
use jedec,spi-nor compatible string for SPI NOR devices and spi-nand
compatible string for SPI NAND devices.

Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>