OMAP3 clock: remove extra init from csi2_96m_fck

csi2_96m_fck no longer should attempt to init its clockdomain pointer; the
clock framework now does this by default.  Applies on top of the "Update
powerdomains and clockdomains" series sent earlier.

Verified on 3430SDP ES2.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>