global_data: Reduce the size of bus_clk and mem_clk

The bus clock and memory clock are unlikely to go above 4GHz for now, so
reduce the field size to 32 bits.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/mips/mach-ath79/ar934x/clk.c b/arch/mips/mach-ath79/ar934x/clk.c
index bdaa683..231a21c 100644
--- a/arch/mips/mach-ath79/ar934x/clk.c
+++ b/arch/mips/mach-ath79/ar934x/clk.c
@@ -327,8 +327,8 @@
 {
 	ar934x_update_clock();
 	printf("CPU:       %8ld MHz\n", gd->cpu_clk / 1000000);
-	printf("Memory:    %8ld MHz\n", gd->mem_clk / 1000000);
-	printf("AHB:       %8ld MHz\n", gd->bus_clk / 1000000);
+	printf("Memory:    %8d MHz\n", gd->mem_clk / 1000000);
+	printf("AHB:       %8d MHz\n", gd->bus_clk / 1000000);
 	return 0;
 }