ARM: clk-imx6sl: Remove csi_lcdif_sels[]

Currently csi_lcdif_sels[] is a shared array for the providing the possible
clock parents for csi and lcdif blocks.

This is not correct, as csi and lcdif do not share the same clock parents.

Introduce csi_sels[] for the csi and lcdif_axi_sels[] for the lcdif clocks in
order to describe the parents correctly.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>