configs: uniphier: Enable CONFIG_SYS_PCI_64BIT

Enable CONFIG_SYS_PCI_64BIT to allow 64bit access to PCI space.
Signed-off-by: NKunihiko Hayashi <hayashi.kunihiko@socionext.com>

include/configs/uniphier.h

@@ -210,4 +210,6 @@
 
 #define CONFIG_SPL_PAD_TO			0x20000
 
+#define CONFIG_SYS_PCI_64BIT
+
 #endif /* __CONFIG_UNIPHIER_H__ */