MAINTAINERS - standardize "T: git urls"

Various forms of "T:        git" entries exist:
git kernel.org:/
git kernel.org/
git://git.kernel.org/
Standardize on "T:  git git://git.kernel.org/<foo>" where appropriate
Fix a few bad git path entries
Signed-off-by: NJoe Perches <joe@perches.com>