documentation: Complete the AMD-S3.txt

Fix some typos and finish empty sections.

Change-Id: I08cc971e763252b035ab8ed2118180140e34ac72
Signed-off-by: Zheng Bao <zheng.bao@amd.com>
Signed-off-by: Zheng Bao <fishbaozi@gmail.com>
Reviewed-on: http://review.coreboot.org/2483
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martin.roth@se-eng.com>
1 file changed