Revert "x86: fsp: Configure SPI opcode registers before SPI is locked down"

This reverts commit 1e6ebee6.

It's not appropriate to call the Intel SPI driver specific stuff in
the FSP codes. We may add a simple DTS property "intel,spi-lock-down"
and let the Intel SPI driver call these stuff instead.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>