staging: ks7010: declare private functions static

Private functions in ks7010_sdio.c can be declared static.

Fixes sparse warnings 'was not declared. Should it be static?'.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>