staging/atomisp: remove sh_css_lace_stat code

I ran into a build warning on my randconfig build box:

drivers/staging/media/atomisp/pci/atomisp2/css2400/sh_css_params.c: In function 'ia_css_lace_statistics_free':
drivers/staging/media/atomisp/pci/atomisp2/css2400/sh_css_params.c:2845:64: error: parameter 'me' set but not used [-Werror=unused-but-set-parameter]

It turns out that not only the parameter is unused but the entire function has no
caller. Let's just remove it.

Fixes: a49d2536 ("staging/atomisp: Add support for the Intel IPU v2")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>