Use the CSIPHY id property to find clock names instead of relying on
generating the clock names based on the control-loop index.
x1e80100 has CSIPHY0, CSIPHY1, CSIPHY2 and CSIPHY4 so simple index naming
won't work whereas and 'id' property allows any ordering and any stepping
between the CSIPHY names.
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>