powerpc/mpc85xx: socrates: rework build process

U-Boot build process for socrates board produces final U-Boot binary in
file u-boot-socrates.bin (by binman) And as a bonus it produces two
unusable broken binaries u-boot-dtb.bin and u-boot.bin (by Makefile).

Clean this up, so final U-Boot binary is in u-boot-dtb.bin

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Heiko Schocher <hs@denx.de>
diff --git a/Makefile b/Makefile
index fa4f38b..518ad39 100644
--- a/Makefile
+++ b/Makefile
@@ -1190,19 +1190,22 @@
 u-boot.bin: u-boot-fit-dtb.bin FORCE
 	$(call if_changed,copy)
 
+ifneq ($(CONFIG_MPC85XX_HAVE_RESET_VECTOR)$(CONFIG_OF_SEPARATE),yy)
 u-boot-dtb.bin: u-boot-nodtb.bin dts/dt.dtb FORCE
 	$(call if_changed,cat)
+endif
 
 else ifeq ($(CONFIG_OF_SEPARATE).$(CONFIG_OF_OMIT_DTB),y.)
+
+ifneq ($(CONFIG_MPC85XX_HAVE_RESET_VECTOR)$(CONFIG_OF_SEPARATE),yy)
 u-boot-dtb.bin: u-boot-nodtb.bin dts/dt.dtb FORCE
 	$(call if_changed,cat)
+endif
 
-ifneq ($(CONFIG_MPC85XX_HAVE_RESET_VECTOR)$(CONFIG_OF_SEPARATE),yy)
 u-boot.bin: u-boot-dtb.bin FORCE
 	$(call if_changed,copy)
-endif
 
-else ifneq ($(CONFIG_MPC85XX_HAVE_RESET_VECTOR)$(CONFIG_OF_SEPARATE),yy)
+else
 u-boot.bin: u-boot-nodtb.bin FORCE
 	$(call if_changed,copy)
 endif
@@ -1581,7 +1584,7 @@
 endif
 
 ifeq ($(CONFIG_MPC85XX_HAVE_RESET_VECTOR)$(CONFIG_OF_SEPARATE),yy)
-u-boot.bin: u-boot-nodtb.bin u-boot.dtb u-boot-br.bin FORCE
+u-boot-dtb.bin: u-boot-nodtb.bin u-boot.dtb u-boot-br.bin FORCE
 	$(call if_changed,binman)
 
 OBJCOPYFLAGS_u-boot-br.bin := -O binary -j .bootpg -j .resetvec