mtd: spi-nor: winbond: Fix locking support for w25q256jwm

mtd: spi-nor: winbond: Fix locking support for w25q256jwm

The Winbond w25q256jwm device supports four Block Protect (BP) bits and
uses Status Register bit 6 as the Top/Bottom (TB) protect bit.

Update the flash parameters by enabling SPI_NOR_4BIT_BP and
SPI_NOR_TB_SR_BIT6. Without these flags, the locking configuration is
incorrect.

Reference:
https://www.winbond.com/hq/support/documentation/levelOne.jsp?__locale=en&DocNo=DA00-W25Q256JW.1

Signed-off-by: Eliav Farber <farbere@amazon.com>
Reviewed-by: Michael Walle <mwalle@kernel.org>
Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>