MX31: fix missing mxc_get_clk() call

Add missing case to be used in common MXC code.
Signed-off-by: NStefano Babic <sbabic@denx.de>

arch/arm/cpu/arm1136/mx31/generic.c

@@ -85,6 +85,7 @@ unsigned int mxc_get_clock(enum mxc_clock clk)
 	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();

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,
 };