omap: McBSP: Fix potential memory leak in omap_mcbsp_remove
Function omap_mcbsp_probe allocates struct omap_mcbsp *mcbsp but it is not
freed in omap_mcbsp_remove. Fix this, remove unneeded structure cleanups
and clk_disable calls since they are not needed here.
This is not problem currently but becomes if the mcbsp driver is ever
modularized.
Signed-off-by: Jarkko Nikula <jhnikula@gmail.com> Signed-off-by: Tony Lindgren <tony@atomide.com>