x86: fsp: Use if() instead of #ifdef

Update a few #ifdefs to if() to improve build coverage.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
[bmeng: recover the codes that got wrongly deleted in dram_init()]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
2 files changed