HID: ntrig: add filtering module parameters

#define NTRIG_DUPLICATE_USAGES	0x001

static unsigned int min_width;

module_param(min_width, uint, 0644);

MODULE_PARM_DESC(min_width, "Minimum touch contact width to accept.");

static unsigned int min_height;

module_param(min_height, uint, 0644);

MODULE_PARM_DESC(min_height, "Minimum touch contact height to accept.");

static unsigned int activate_slack = 1;

module_param(activate_slack, uint, 0644);

MODULE_PARM_DESC(activate_slack, "Number of touch frames to ignore at "

		 "the start of touch input.");

static unsigned int deactivate_slack = 4;

module_param(deactivate_slack, uint, 0644);

MODULE_PARM_DESC(deactivate_slack, "Number of empty frames to ignore before "

		 "deactivating touch.");

static unsigned int activation_width = 64;

module_param(activation_width, uint, 0644);

MODULE_PARM_DESC(activation_width, "Width threshold to immediately start "

		 "processing touch events.");

static unsigned int activation_height = 32;

module_param(activation_height, uint, 0644);

MODULE_PARM_DESC(activation_height, "Height threshold to immediately start "

		 "processing touch events.");

struct ntrig_data {

	/* Incoming raw values for a single contact */