utils/test-pkg: fix long option parsing

utils/test-pkg: fix long option parsing

The long option parsing of test-pkg is broken because:
- some long options are not declared
- there should be a comma between long options, the colon does not replace
it.

This change also revealed that the declaration of 'toolchains-dir' should
have been 'toolchains-csv', originally introduced in commit ed59f81a3cb4ddb.

Signed-off-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
Acked-by: Yann E. MORIN <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>