format-code: detect tcl files

openbmc-test-automation has a few tcl files which are incorrectly
identified as bash by the `file` utility.  Explicitly catch this
extension and classify as 'tcl' even though we don't have a linter
for that language.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I2bb45b21398819d6a73cfa99aa1b5ef5f4bed164
1 file changed