board: engicam: Attach i.MX6 common code

The existing common code for Engicam boards uses i.MX6,
so attach that into i.MX6 Engicam boards so-that adding
new SoC variants of Engicam boards become meaningful.

Add support for it.

Cc: Stefano Babic <sbabic@denx.de>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Kever Yang<kever.yang@rock-chips.com>
diff --git a/board/engicam/common/Makefile b/board/engicam/common/Makefile
index b392bf6..15f0eaa 100644
--- a/board/engicam/common/Makefile
+++ b/board/engicam/common/Makefile
@@ -1,5 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0+
 # Copyright (C) 2016 Amarula Solutions B.V.
 
-obj-y := board.o
-obj-$(CONFIG_SPL_BUILD) += spl.o
+ifdef CONFIG_SPL_BUILD
+obj-$(CONFIG_IMX6_ENGICAM_COMMON) += spl.o
+else
+obj-$(CONFIG_IMX6_ENGICAM_COMMON) += board.o
+endif