mfd: ti_am335x_tscadc: Drop unused definitions from the header

The STEP ENABLE definitions are highly unclear and not used so drop them.
Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-27-miquel.raynal@bootlin.com

include/linux/mfd/ti_am335x_tscadc.h

@@ -39,13 +39,6 @@
 /* IRQ wakeup enable */
 #define IRQWKUP_ENB		BIT(0)
 
-/* Step Enable */
-#define STEPENB_MASK		(0x1FFFF << 0)
-#define STEPENB(val)		((val) << 0)
-#define ENB(val)		(1 << (val))
-#define STPENB_STEPENB		STEPENB(0x1FFFF)
-#define STPENB_STEPENB_TC	STEPENB(0x1FFF)
-
 /* IRQ enable */
 #define IRQENB_HW_PEN		BIT(0)
 #define IRQENB_EOS		BIT(1)