x86: cpu: i386: cpu: only set pci_ram_top if CONFIG_IS_ENABLED(PCI)

This avoids an error when ifdef CONFIG_PCI is changed to
if CONFIG_IS_ENABLED(PCI)

Signed-off-by: Troy Kisky <troykiskyboundary@gmail.com>
[Rebased on top of u-boot/master]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h
index 8fc205d..d364f1b 100644
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -573,6 +573,13 @@
 #define gd_malloc_start()	0
 #define gd_set_malloc_start(val)
 #endif
+
+#if CONFIG_IS_ENABLED(PCI)
+#define gd_set_pci_ram_top(val)	gd->pci_ram_top = val
+#else
+#define gd_set_pci_ram_top(val)
+#endif
+
 /**
  * enum gd_flags - global data flags
  *