N1SDP: Initialise CNTFRQ in Non Secure CNTBaseN

N1SDP: Initialise CNTFRQ in Non Secure CNTBaseN

N1SDP exhibits the behavior similar to Juno wherein CNTBaseN.CNTFRQ
can be written but does not reflect the value of the CNTFRQ register
in CNTCTLBase frame. This doesn't follow ARM ARM in that the value
updated in CNTCTLBase.CNTFRQ is not reflected in CNTBaseN.CNTFRQ.

Hence enable the workaround (applied to Juno) for N1SDP that updates
the CNTFRQ register in the Non Secure CNTBaseN frame.

Change-Id: Id89ee1bca0f25c9d62f8f794f2c4f4e618cdf092
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>