x86: doc: Minor update for accuracy

This updates the doc for the following places:
- Mention CRB for Bayley Bay
- Mention Congatec QEVAL 2.0 & conga-QA3/E3845
- Limit part of the QEMU paragraphs to 80 cols
- Correct some typos (drive, it's, Ubuntu)
- Add description for "console=ttyS0,115200"
- Remove CONFIG_BOOTDELAY description which is already
  in x86-common.h

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Tested-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>