4BA: Allow disabling 4-byte address mode for SPI flash

This allows us to support flash chips in any of the following
configurations, regardless of whether the chip powers up in 3-byte or
4-byte address mode.

- standard commands with extended address register (*_4ba_ereg) or
  direct commands (*_4ba_direct) in 3-byte address mode (.set_4ba =
- standard commands (*_4ba) or direct commands (*_4ba_direct) in
  4-byte address mode (.set_4ba = spi_enter_4ba_*)
- direct commands (*_4ba_direct) in either address mode (.set_4ba =

Change-Id: I0b25309d731426940fc50956b744b681ab599e87
Signed-off-by: Ed Swierk <eswierk@skyportsystems.com>
Reviewed-on: https://review.coreboot.org/20510
Reviewed-by: David Hendricks <david.hendricks@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
3 files changed