MIPS: Make the debugging of compressed kernel configurable

This patch adds a new DEBUG_ZBOOT option to allow the users to enable it
to debug the compressed kernel support for a new board and this optoin
should be disabled to reduce the kernel image size and speed up the
kernel booting procedure when the compressed kernel support is stable.

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
To: Ralf Baechle <ralf@linux-mips.org>
Cc: Manuel Lauss <manuel.lauss@googlemail.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/918/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile
index 76d6930..790ddd3 100644
--- a/arch/mips/boot/compressed/Makefile
+++ b/arch/mips/boot/compressed/Makefile
@@ -35,8 +35,10 @@
 
 obj-y := $(obj)/head.o $(obj)/decompress.o $(obj)/dbg.o
 
+ifdef CONFIG_DEBUG_ZBOOT
 obj-$(CONFIG_SYS_SUPPORTS_ZBOOT_UART16550) += $(obj)/uart-16550.o
 obj-$(CONFIG_MACH_ALCHEMY)		   += $(obj)/uart-alchemy.o
+endif
 
 OBJCOPYFLAGS_vmlinux.bin := $(OBJCOPYFLAGS) -O binary -R .comment -S
 $(obj)/vmlinux.bin: $(KBUILD_IMAGE)