The INSN_CONFIG_FILTER instruction is used to set the deglitch filter
interval used to debounce the input channels.
Absorb the helper function into the (*insn_config) function and refactor
the code to not require the 'filter_interval' and 'filter_enable' members
in the private data.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Reviewed-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>