[PATCH 3/6] arm/imx: change mxc_init_l2x0() to an imx31/35 specific call

[Shawn Guo]

The mxc_init_l2x0() should really be an imx31/35 specific call.
The patch removes early_initcall from mxc_init_l2x0() and get imx31
and imx35 soc specific function calls mxc_init_l2x0(), so that it's
not necessarily to be called for all imx socs when we build single
image for multiple imx socs.

Thus the function can be renamed to imx3_init_l2x0() and put into
mm-imx3.c.  It also changes the return type from integer to void.