mx5 clocks: Fix get_ipg_per_clk()

This fixes the "IPG PERCLK" frequency printed by the clocks command. The issue
was that get_ipg_per_clk() used periph_clk instead of lp_apm in the case
CCM.CBCMR.perclk_lp_apm_sel is set.

It also fixes I²C support.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Cc: Stefano Babic <sbabic@denx.de>

arch/arm/cpu/armv7/mx5/clock.c

@@ -315,16 +315,20 @@ static u32 get_ipg_clk(void)
  */
 static u32 get_ipg_per_clk(void)
 {
-	u32 pred1, pred2, podf;
+	u32 freq, pred1, pred2, podf;
 
 	if (readl(&mxc_ccm->cbcmr) & MXC_CCM_CBCMR_PERCLK_IPG_CLK_SEL)
 		return get_ipg_clk();
-	/* Fixme: not handle what about lpm*/
+
+	if (readl(&mxc_ccm->cbcmr) & MXC_CCM_CBCMR_PERCLK_LP_APM_CLK_SEL)
+		freq = get_lp_apm();
+	else
+		freq = get_periph_clk();
 	podf = readl(&mxc_ccm->cbcdr);
 	pred1 = MXC_CCM_CBCDR_PERCLK_PRED1_RD(podf);
 	pred2 = MXC_CCM_CBCDR_PERCLK_PRED2_RD(podf);
 	podf = MXC_CCM_CBCDR_PERCLK_PODF_RD(podf);
-	return get_periph_clk() / ((pred1 + 1) * (pred2 + 1) * (podf + 1));
+	return freq / ((pred1 + 1) * (pred2 + 1) * (podf + 1));
 }
 
 /*