S3C64XX: Fix ARMCLK configuration

The value of armclk_mask needs to be inverted for use as a mask on
the register value when updating ARM_RATIO.

This is critical for cpufreq support, without it attempts to scale
the frequency of the core trash pretty much the entire clock tree.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

arch/arm/plat-s3c64xx/s3c6400-clock.c

@@ -175,7 +175,7 @@ static int s3c64xx_clk_arm_set_rate(struct clk *clk, unsigned long rate)
 	div = clk_get_rate(clk->parent) / rate;
 
 	val = __raw_readl(S3C_CLK_DIV0);
-	val &= armclk_mask;
+	val &= ~armclk_mask;
 	val |= (div - 1);
 	__raw_writel(val, S3C_CLK_DIV0);