x86: quark: Drop unprotect_spi_flash()

Unprotecting SPI flash is now handled in the SPI controller driver,
via a call to the PCH driver. Drop the ad-hoc version.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
1 file changed