Drop rb5-userdebug build target and use db845c-userdebug for RB5

We have been using db845c-userdebug target builds to support
DB845c (RB3) and RB5 devboards for a long time now. So it is
time to formally drop rb5-userdebug build target from AOSP.

The RB5 flashing instructions in installer/rb5/ remain the same.
The device documentation as available from "Android Reference
Boards" page https://source.android.com/docs/setup/create/devices
is already updated.

Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Change-Id: I2af594bfd23f7b963d65e9b50a38389b292f56cf
diff --git a/AndroidProducts.mk b/AndroidProducts.mk
index a7b4476..2479437 100644
--- a/AndroidProducts.mk
+++ b/AndroidProducts.mk
@@ -12,12 +12,8 @@
 PRODUCT_MAKEFILES := \
     $(LOCAL_DIR)/db845c.mk \
     $(LOCAL_DIR)/db845c_mini.mk \
-    $(LOCAL_DIR)/rb5.mk \
-    $(LOCAL_DIR)/rb5_mini.mk \
     $(LOCAL_DIR)/sm8450_mini.mk \
     $(LOCAL_DIR)/linaro_swr.mk \
 
 COMMON_LUNCH_CHOICES := \
-    db845c-trunk_staging-userdebug \
-    rb5-trunk_staging-userdebug \
-
+    db845c-trunk_staging-userdebug