Remove AOSP reference to utils.mk

Remove function calls from AOSP code to utils.mk
& replace them with actual definition.

Change-Id: Id14a111259c9a3d63654bbde285657635525d206
CRs-fixed: 566287
diff --git a/AndroidBoot.mk b/AndroidBoot.mk
index 1cb0322..6637405 100644
--- a/AndroidBoot.mk
+++ b/AndroidBoot.mk
@@ -13,7 +13,7 @@
   SIGNED_KERNEL := SIGNED_KERNEL=0
 endif
 
-ifeq ($(call is-board-platform,msm8660),true)
+ifeq ($(TARGET_BOARD_PLATFORM),msm8660)
   BOOTLOADER_PLATFORM := msm8660_surf
 else
   BOOTLOADER_PLATFORM := $(TARGET_BOARD_PLATFORM)