Build arch/$ARCH/lib/bootm.o depending on CONFIG_CMD_BOOTM

MAKEALL is fine for ppc4xx and mpc85xx.
Run checks were done on our controlcenterd hardware.

Signed-off-by: Dirk Eibach <dirk.eibach@gdsys.cc>
Signed-off-by: Andy Fleming <afleming@freescale.com>
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index f66ad30..ab3ccee 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -25,7 +25,7 @@
 
 LIB	= $(obj)lib$(ARCH).o
 
-COBJS-y	+= bootm.o
+COBJS-$(CONFIG_CMD_BOOTM) += bootm.o
 COBJS-y	+= cmd_boot.o
 COBJS-y	+= gcc.o
 COBJS-y	+= init_helpers.o