drivers: flash: 4 byte address mode fix, if write enable is required

This fixes this bug:
https://github.com/zephyrproject-rtos/zephyr/issues/57498


If bit 1 is set, then a write enable is required before
sending the 0xb7 instruction to enable the 4 byte address
mode, which this PR implements.

Signed-off-by: Frank Buss <fb@frank-buss.de>