i.MX31: Fix PRCS bit test

cppcheck detected a condition which was always false.

According to the MCIMX31 Reference Manual, the PRCS bits have to be 01
to select the Frequency Pre-Multiplier (FPM). PRCS uses bits 1 and 2,
so we have to test for 2.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NPeter Chubb <peter.chubb@nicta.com.au>
Message-id: 1370810662-32320-1-git-send-email-sw@weilnetz.de
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

hw/misc/imx_ccm.c

@@ -153,7 +153,7 @@ static void update_clocks(IMXCCMState *s)
      * approach
      */
 
-    if ((s->ccmr & CCMR_PRCS) == 1) {
+    if ((s->ccmr & CCMR_PRCS) == 2) {
         s->pll_refclk_freq = CKIL_FREQ * 1024;
     } else {
         s->pll_refclk_freq = CKIH_FREQ;