i2c: rk3x: Fix sparse warning

This patch fixes the following sparse warning:
drivers/i2c/busses/i2c-rk3x.c:888:17: warning: cast truncates bits from constant value (ffffffffff00 becomes ffffff00)
Reported-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NDavid Wu <david.wu@rock-chips.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-rk3x.c

@@ -58,7 +58,7 @@ enum {
 #define REG_CON_LASTACK   BIT(5) /* 1: send NACK after last received byte */
 #define REG_CON_ACTACK    BIT(6) /* 1: stop if NACK is received */
 
-#define REG_CON_TUNING_MASK GENMASK(15, 8)
+#define REG_CON_TUNING_MASK GENMASK_ULL(15, 8)
 
 #define REG_CON_SDA_CFG(cfg) ((cfg) << 8)
 #define REG_CON_STA_CFG(cfg) ((cfg) << 12)