mtd: m25p80: Use OPCODE_QUAD_READ_4B for 4-byte addressing

commit 3487a639

 ("drivers: mtd: m25p80: add
quad read support") in -next added both the 3-byte OPCODE_QUAD_READ and the
4-byte OPCODE_QUAD_READ_4B, but incorrectly uses OPCODE_QUAD_READ for both
3-byte and 4-byte addressing.

Use OPCODE_QUAD_READ_4B in the 4-byte case to fix this.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>