mx31ads: fix 32kHz clock handling

According to schematics and to RedBoot sources, the MX31ADS uses a 32768Hz
oscillator as a SKIL source. Fix previously wrongly assumed 32000Hz value.
Also fix a typo when verifying a jumper configuration. While at it, make
two needlessly global functions static.

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
diff --git a/cpu/arm1136/mx31/generic.c b/cpu/arm1136/mx31/generic.c
index 16b2cf1..29c08c1 100644
--- a/cpu/arm1136/mx31/generic.c
+++ b/cpu/arm1136/mx31/generic.c
@@ -39,7 +39,7 @@
 		(mfd * pd)) << 10;
 }
 
-u32 mx31_get_mpl_dpdgck_clk(void)
+static u32 mx31_get_mpl_dpdgck_clk(void)
 {
 	u32 infreq;
 
@@ -51,7 +51,7 @@
 	return mx31_decode_pll(__REG(CCM_MPCTL), infreq);
 }
 
-u32 mx31_get_mcu_main_clk(void)
+static u32 mx31_get_mcu_main_clk(void)
 {
 	/* For now we assume mpl_dpdgck_clk == mcu_main_clk
 	 * which should be correct for most boards