AndroidKernel: add support to configure DLKM install path

Add support to configure DLKM install path.

TARGET_OUT is hard coded to system directory.
Use PRODUCT_OUT instead of TARGET_OUT to use user configured path
instead.

Change-Id: Iacbfa0fce69d3cb4b6f47a6c857983034633dc19
Signed-off-by: Shashank Mittal <mittals@codeaurora.org>
Signed-off-by: Puja Gupta <pujag@codeaurora.org>
diff --git a/AndroidKernel.mk b/AndroidKernel.mk
index b5f7dac..2a8d506 100644
--- a/AndroidKernel.mk
+++ b/AndroidKernel.mk
@@ -95,8 +95,8 @@
 endif
 
 KERNEL_HEADERS_INSTALL := $(KERNEL_OUT)/usr
-KERNEL_MODULES_INSTALL := system
-KERNEL_MODULES_OUT := $(TARGET_OUT)/lib/modules
+KERNEL_MODULES_INSTALL ?= system
+KERNEL_MODULES_OUT ?= $(PRODUCT_OUT)/$(KERNEL_MODULES_INSTALL)/lib/modules
 
 TARGET_PREBUILT_KERNEL := $(TARGET_PREBUILT_INT_KERNEL)