staging:iio:ad2s1210: Remove unused #define directive

#define AD2S1210_SET_RES1		0x02

#define AD2S1210_SET_RES0		0x01

#define AD2S1210_SET_ENRESOLUTION	(AD2S1210_SET_ENRES1 |	\

					 AD2S1210_SET_ENRES0)

#define AD2S1210_SET_RESOLUTION		(AD2S1210_SET_RES1 | AD2S1210_SET_RES0)

#define AD2S1210_REG_POSITION		0x80

#define AD2S1210_REG_SOFT_RESET		0xF0

#define AD2S1210_REG_FAULT		0xFF

/* pin SAMPLE, A0, A1, RES0, RES1, is controlled by driver */

#define AD2S1210_SAA		3

#define AD2S1210_PN		(AD2S1210_SAA + AD2S1210_RES)

#define AD2S1210_MIN_CLKIN	6144000

#define AD2S1210_MAX_CLKIN	10240000

#define AD2S1210_MIN_EXCIT	2000

#define AD2S1210_MIN_FCW	0x4

#define AD2S1210_MAX_FCW	0x50

/* default input clock on serial interface */

#define AD2S1210_DEF_CLKIN	8192000

/* clock period in nano second */

#define AD2S1210_DEF_TCK	(1000000000 / AD2S1210_DEF_CLKIN)

#define AD2S1210_DEF_EXCIT	10000

enum ad2s1210_mode {