clk: imx6sl: correct ocram_podf clock type

IMX6SL_CLK_OCRAM_PODF is a busy divider, its name in
CCM_CDHIPR register of Reference Manual CCM chapter
is axi_podf_busy, correct its clock type.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Acked-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>