n25q256ax1 [1] uses the 4 bit Block Protection scheme and supports
Top/Bottom protection via the BP and TB bits of the Status Register.
BP3 is located in bit 6 of the Status Register.
Tested on n25q256ax1.
[1] https://www.micron.com/-/media/client/global/documents/products/data-sheet/nor-flash/serial-nor/n25q/n25q_256mb_3v.pdf
Signed-off-by: Eliav Farber <farbere@xxxxxxxxxx>