documentation update
documentation update

Update README file to reflect some major changes in the project:

Introduce API and libraries

arch-agnostic EFI build

remove dependencies in EFI build

Signed-off-by: Jianxun Zhang <cf37b857570b0701d39fd0feb77f6a52483b5c8d@linux.intel.com>

todorez/rmc,todorez/rmc