MX31: fix missing mxc_get_clk() call

Add missing case to be used in common MXC code.

Signed-off-by: Stefano Babic <sbabic@denx.de>
diff --git a/arch/arm/cpu/arm1136/mx31/generic.c b/arch/arm/cpu/arm1136/mx31/generic.c
index 248431b..e3a4d1b 100644
--- a/arch/arm/cpu/arm1136/mx31/generic.c
+++ b/arch/arm/cpu/arm1136/mx31/generic.c
@@ -85,6 +85,7 @@
 	case MXC_ARM_CLK:
 		return mx31_get_mcu_main_clk();
 	case MXC_IPG_CLK:
+	case MXC_IPG_PERCLK:
 	case MXC_CSPI_CLK:
 	case MXC_UART_CLK:
 		return mx31_get_ipg_clk();
diff --git a/arch/arm/include/asm/arch-mx31/clock.h b/arch/arm/include/asm/arch-mx31/clock.h
index b132676..cc99a75 100644
--- a/arch/arm/include/asm/arch-mx31/clock.h
+++ b/arch/arm/include/asm/arch-mx31/clock.h
@@ -27,6 +27,7 @@
 enum mxc_clock {
 	MXC_ARM_CLK,
 	MXC_IPG_CLK,
+	MXC_IPG_PERCLK,
 	MXC_CSPI_CLK,
 	MXC_UART_CLK,
 };