Removing internal links from README.
Removing internal links from README.

Change-Id: Iac7497589362b6117f26bbd0512cdbe0d3b4b4cf

project-oak/hafnium-verification,project-oak/hafnium-verification,project-oak/hafnium-verification,project-oak/hafnium-verification,project-oak/hafnium-verification,project-oak/hafnium-verification,project-oak/hafnium-verification