UnitTestFrameworkPkg: Use TianoCore mirror of subhook submodule

Change subhook url from https://github.com/Zeex/subhook to
https://github.com/tianocore/edk2-subhook because old url is
no longer available.

Also align .gitmodules file to use consistent LF line endings.

Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>