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-octeon/cpu.c b/arch/mips/mach-octeon/cpu.c
index c7744e8..c771da6 100644
--- a/arch/mips/mach-octeon/cpu.c
+++ b/arch/mips/mach-octeon/cpu.c
@@ -67,7 +67,7 @@
 	gd->cpu_clk = ref_clock * FIELD_GET(RST_BOOT_C_MUL, val);
 	gd->bus_clk = ref_clock * FIELD_GET(RST_BOOT_PNR_MUL, val);
 
-	debug("%s: cpu: %lu, bus: %lu\n", __func__, gd->cpu_clk, gd->bus_clk);
+	debug("%s: cpu: %lu, bus: %u\n", __func__, gd->cpu_clk, gd->bus_clk);
 
 	return 0;
 }