ppc: arm: Move sdhc_clk into arch_global_data

This is used by both powerpc and arm, but I think it still qualifies as
architecture-specific.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/cpu/arm1136/mx35/generic.c b/arch/arm/cpu/arm1136/mx35/generic.c
index 295a98e..d11e6f6 100644
--- a/arch/arm/cpu/arm1136/mx35/generic.c
+++ b/arch/arm/cpu/arm1136/mx35/generic.c
@@ -478,11 +478,11 @@
 {
 #ifdef CONFIG_FSL_ESDHC
 #if CONFIG_SYS_FSL_ESDHC_ADDR == MMC_SDHC2_BASE_ADDR
-	gd->sdhc_clk = mxc_get_clock(MXC_ESDHC2_CLK);
+	gd->arch.sdhc_clk = mxc_get_clock(MXC_ESDHC2_CLK);
 #elif CONFIG_SYS_FSL_ESDHC_ADDR == MMC_SDHC3_BASE_ADDR
-	gd->sdhc_clk = mxc_get_clock(MXC_ESDHC3_CLK);
+	gd->arch.sdhc_clk = mxc_get_clock(MXC_ESDHC3_CLK);
 #else
-	gd->sdhc_clk = mxc_get_clock(MXC_ESDHC1_CLK);
+	gd->arch.sdhc_clk = mxc_get_clock(MXC_ESDHC1_CLK);
 #endif
 #endif
 	return 0;