OMAP4: Clock: Correct OTG clock to use otg_60m_gfclk.

OTG clock usb_otg_hs_ick used a incorrect parent l3_div_ck.
Correct it to use the right colck otg_60m_gfclk as its
parent.

Change-Id: Ibf8232e4e0081277249d6198e12e170e7550dc15
Signed-off-by: Wenbiao Wang <wwang@ti.com>