AMD/Bettong: add function to read board version

Bettong uses 3 GPIO(5-7) pins to identify board.
The GPIO ports are mapped to MMIO space.
The GPIO value and board version are mapped as follow:
GPIO5 GPIO6 GPIO7 Version
  0     0     0      A
  0     0     1      B
  ......
  1     1     1      H

Change-Id: I72df28043057d8c4ccc4a2e645011ca5379e9928
Signed-off-by: WANG Siyuan <wangsiyuanbuaa@gmail.com>
Signed-off-by: WANG Siyuan <SiYuan.Wang@amd.com>
Signed-off-by: Zheng Bao <fishbaozi@gmail.com>
Reviewed-on: http://review.coreboot.org/11732
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

0 files changed, 0 insertions, 0 deletions