iio: adc: twl4030: Drop struct twl4030_madc_user_parms

This struct is no longer used by anything in the kernel.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

include/linux/i2c/twl4030-madc.h

@@ -135,10 +135,4 @@ enum sample_type {
 #define TWL4030_REG_GPBR1		0x0c
 #define TWL4030_GPBR1_MADC_HFCLK_EN	(1 << 7)
 
-struct twl4030_madc_user_parms {
-	int channel;
-	int average;
-	int status;
-	u16 result;
-};
 #endif