doc,oeqa/cam: Wait for the clock to be in sync on virtualization

When the virtualization architecture is used, the DomU1 and DomU2
clocks need to be synchronized with the Dom0 clock before running
CAM, currently there is no check for this condition.

Add a check in the OEQA test that ensure the clock is synchronized
and update the documentation to add this step before running CAM.

Add a missing word to the dictionary to please the spellchecker.

Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>