ARM: ux500: fix clock for GPIO block 8

The clock assignment in the device tree for GPIO block 8 was
incorrect, indicating this was managed by bit 1 on PRCC 6
while it was in fact bit 1 on PRCC 5.
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/boot/dts/ste-dbx5x0.dtsi

@@ -227,7 +227,7 @@ gpio8: gpio@a03fe000 {
 			#gpio-cells = <2>;
 			gpio-bank = <8>;
 
-			clocks = <&prcc_pclk 6 1>;
+			clocks = <&prcc_pclk 5 1>;
 		};
 
 		pinctrl {