include: Add version info to struct sbi_platform

Add version control of sbi_platform structure
- Add opensbi_version, this gives information of opensbi revision on
which the sbi_platform table was created.
- Add platform_version field in sbi_platform structure for platform
level version control.

Signed-off-by: Abner Chang <abner.chang@hpe.com>
Acked-by: Anup Patel <anup.patel@wdc.com>