db845c: firmware: Restrict to db845c

Include the db845c/firmware directory in build only for db845c
target.

This allows us to add locally the firmware for pixel3_mainline target.

Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Change-Id: I4f3ebcb290243be7e168b42c24a826b994791020
diff --git a/db845c/firmware/Android.mk b/db845c/firmware/Android.mk
index 8f5f09c..3af24e3 100644
--- a/db845c/firmware/Android.mk
+++ b/db845c/firmware/Android.mk
@@ -1,3 +1,5 @@
+ifneq ($(filter db845c, $(TARGET_BOARD_PLATFORM)),)
+
 LOCAL_PATH := $(call my-dir)
 
 include device/linaro/dragonboard/utils.mk
@@ -113,3 +115,4 @@
 $(foreach f, $(ath10k_firmware_files), $(call add-qcom-firmware, $(f), $(TARGET_OUT_VENDOR)/firmware/ath10k/WCN3990/hw1.0/))
 
 include $(call all-makefiles-under,$(LOCAL_PATH))
+endif