[make] Cleanup overlay processing order

Add LKROOT to LKINC only if it is not already there.
This would allow to specify particular overlay processing
order if required.

Remove adding separate LKROOT/include to GLOBAL_DEFINES as
It is already a part of LKINC list.

Add all directories specified by LKINC to GLOBAL_LDFLAGS instead
of just LKROOT

Change-Id: Ia61623f88f2c5978182c40b09d98b6e5b84e3955

engine.mk

@@ -49,7 +49,7 @@ OUTBIN := $(BUILDDIR)/lk.bin
 OUTELF := $(BUILDDIR)/lk.elf
 CONFIGHEADER := $(BUILDDIR)/config.h
 
-GLOBAL_INCLUDES := $(BUILDDIR) $(LKROOT)/include $(addsuffix /include,$(LKINC))
+GLOBAL_INCLUDES := $(BUILDDIR) $(addsuffix /include,$(LKINC))
 GLOBAL_OPTFLAGS ?= $(ARCH_OPTFLAGS)
 GLOBAL_COMPILEFLAGS := -g -fno-builtin -finline -W -Wall -Wno-multichar -Wno-unused-parameter -Wno-unused-function -include $(CONFIGHEADER)
 GLOBAL_CFLAGS := --std=gnu99 -Werror-implicit-function-declaration -Wstrict-prototypes -Wwrite-strings
@@ -59,7 +59,7 @@ GLOBAL_CPPFLAGS := -fno-exceptions -fno-rtti -fno-threadsafe-statics
 GLOBAL_ASMFLAGS := -DASSEMBLY
 GLOBAL_LDFLAGS :=
 
-GLOBAL_LDFLAGS += -L $(LKROOT)
+GLOBAL_LDFLAGS += $(addprefix -L,$(LKINC))
 
 # top level rule
 all:: $(OUTBIN) $(OUTELF).lst $(OUTELF).debug.lst $(OUTELF).sym $(OUTELF).sym.sorted $(OUTELF).size

makefile

@@ -9,7 +9,10 @@ BUILDROOT ?= .
 DEFAULT_PROJECT ?=
 TOOLCHAIN_PREFIX ?=
 
+# check if LKROOT is already a part of LKINC list and add it only if it is not
+ifneq ($(findstring $(LKROOT),$(LKINC)), $(LKROOT))
 LKINC := $(LKROOT) $(LKINC)
+endif
 
 export LKMAKEROOT
 export LKROOT