This reverts commit d7f21940bc.
Winbond W25Q256FV and W25Q256JV both uses 0xef4019 as JEDEC ID,
but only the latter has proper 4B_OPCODES support.
W25Q256FV has all 4B read instructions but it lacks a 4B page program
instruction, causing the entire flash to be read-only.
Signed-off-by: Chuanhong Guo <gch981213@gmail.com>