[msm7630] Drop unified boot header

Drop unified boot header as we are not expecting osbl to load boot.img
Save osbl from checking the header and attempting to load boot.img as
it also helps boot time performance.

Change-Id: I1c4138dcd5bc2b5b669aa69c82dcbf9290ec4d5b
diff --git a/target/msm7630_surf/tools/makefile b/target/msm7630_surf/tools/makefile
index 4082eee..db458e6 100644
--- a/target/msm7630_surf/tools/makefile
+++ b/target/msm7630_surf/tools/makefile
@@ -35,7 +35,7 @@
 	rm -f $(APPSBOOTHEADER_DIR)/emmc_appsboothd.mbn
 
 emmc_appsboothd.mbn: mkheader $(OUTBIN)
-	$(SRC_DIR)/mkheader $(OUTBIN) $(APPSBOOTHEADER_DIR)/emmc_appsboothd.mbn unified-boot
+	$(SRC_DIR)/mkheader $(OUTBIN) $(APPSBOOTHEADER_DIR)/emmc_appsboothd.mbn
 
 mkheader: $(SRC_DIR)/mkheader.c
 	${COMPILER} -DMEMBASE=$(MEMBASE) $(SRC_DIR)/mkheader.c -o $(SRC_DIR)/mkheader