uniphier: extend boot device detection for future SoCs

The next SoC will have:
  - No boot swap
  - SD boot
  - No USB boot

Add new fields to handle this.

Change-Id: I772395f2c5dfc612e575b0cbd0657a5fa9611c25
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2 files changed