Update .gitignore
Created by: sudeep-holla
This patch updates .gitignore file to ignore patch files(often generated by git format-patch) and cscope index files(similar to ctags)
Change-Id: I134631306e7741e9e2e4e8d4a86c2f84f5166f77 Signed-off-by: Sudeep Holla sudeep.holla@arm.com