Bluetooth: Validate PSM values in calls to connect() and bind()

Valid L2CAP PSMs are odd numbers, and the least significant bit of the
most significant byte must be 0.

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>