i2c: brcmstb: remove unused struct member

No further occurences in the driver.

Fixes: dd1aa252 ("i2c: brcmstb: Add Broadcom settop SoC i2c controller driver")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-brcmstb.c

@@ -165,7 +165,6 @@ static const struct bsc_clk_param bsc_clk[] = {
 struct brcmstb_i2c_dev {
 	struct device *device;
 	void __iomem *base;
-	void __iomem *irq_base;
 	int irq;
 	struct bsc_regs *bsc_regmap;
 	struct i2c_adapter adapter;