api: export LCD device to external apps

This patch exports LCD info-query and bitmap-rendering functions to
external apps.

This patch is tested on a Seaboard.  Because the LCD driver is not yet
upstreamed, the test was done in a local downstream repo.

Signed-off-by: Che-Liang Chiou <clchiou@chromium.org>
diff --git a/api/Makefile b/api/Makefile
index 2a64c4d..0e99f74 100644
--- a/api/Makefile
+++ b/api/Makefile
@@ -24,7 +24,8 @@
 
 LIB	= $(obj)libapi.o
 
-COBJS-$(CONFIG_API) += api.o api_net.o api_storage.o api_platform-$(ARCH).o
+COBJS-$(CONFIG_API) += api.o api_display.o api_net.o api_storage.o \
+		       api_platform-$(ARCH).o
 
 COBJS	:= $(COBJS-y)
 SRCS	:= $(COBJS:.o=.c)