test: Bluetooth: EDTT: Disable invalid tests

Some tests assume that if IUT accepted HCI_LE_Set_Data_Length command
than HCI_LE_Data_Length_Change event will always be sent. This is not
the case anymore as HCI_LE_Data_Length_Change is sent only if effective
parameters changed.

Those tests should be re-enabled when EDDT implementation is updated.

Signed-off-by: Szymon Janc <szymon.janc@codecoup.pl>