dts: bindings: flash_controller: stm32-ospi-nor: add 4byte opcodes property

Adds `four-byte-opcodes` property. When set, then used write and read
opcodes will be converted to 4-Byte opcode.

Doesn't convert erase opcodes yet.

Signed-off-by: Georgij Cernysiov <geo.cgv@gmail.com>