readme was missing instructions to build M2B. Now added.
Signed-off-by: Andrea Calabrese <andrea.calabrese@amarulasolutions.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
The primary upstream URL for tf-a has moved, in some cases
things like tags are not always pushed to the old URL so
update the URLs to the primary upstream project URL.
Signed-off-by: Peter Robinson <pbrobinson@gmail.com>