i2c: cadence: Remove unused CDNS_I2C_DATA_INTR_DEPTH define

The CDNS_I2C_DATA_INTR_DEPTH is not used in the Cadence I2C driver. Remove
it.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/busses/i2c-cadence.c

@@ -115,8 +115,6 @@
 #define CNDS_I2C_PM_TIMEOUT		1000	/* ms */
 
 #define CDNS_I2C_FIFO_DEPTH		16
-/* FIFO depth at which the DATA interrupt occurs */
-#define CDNS_I2C_DATA_INTR_DEPTH	(CDNS_I2C_FIFO_DEPTH - 2)
 #define CDNS_I2C_MAX_TRANSFER_SIZE	255
 /* Transfer size in multiples of data interrupt depth */
 #define CDNS_I2C_TRANSFER_SIZE	(CDNS_I2C_MAX_TRANSFER_SIZE - 3)