ARM: dts: Fix CLK_UART_ISP_SCLK clock assignment in exynos4x12.dtsi

Assign proper FIMC-IS UART gate clock in the device DT node and not
use the SRC_MASK gate. This fixes regression introduced in commit
a37c82a3 ("clk: samsung: exynos4: Remove
SRC_MASK_ISP gates").

Without this change exynos4 fimc-is driver fails to probe with an
error log:

[    1.842447] ERROR: could not get clock /camera/fimc-is@12000000:uart(13)
[    1.848529] exynos4-fimc-is 12000000.fimc-is: failed to get clock: uart
[    1.855275] exynos4-fimc-is: probe of 12000000.fimc-is failed with error -2
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kukjin Kim <kgene@kernel.org>

arch/arm/boot/dts/exynos4x12.dtsi

@@ -226,7 +226,7 @@ fimc_is: fimc-is@12000000 {
 				 <&clock CLK_DIV_ISP0>,<&clock CLK_DIV_ISP1>,
 				 <&clock CLK_DIV_MCUISP0>,
 				 <&clock CLK_DIV_MCUISP1>,
-				 <&clock CLK_SCLK_UART_ISP>,
+				 <&clock CLK_UART_ISP_SCLK>,
 				 <&clock CLK_ACLK200>, <&clock CLK_DIV_ACLK200>,
 				 <&clock CLK_ACLK400_MCUISP>,
 				 <&clock CLK_DIV_ACLK400_MCUISP>;