amlogic: console: Move console driver to common directory

The code managing the console is the same for all the platforms
currently supported. Since it is unlikely to change in the future move
the code to an external file in the common directory.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
Change-Id: I6df555ea82d483b4f08a4a1e2cb0a7488fbaa015
diff --git a/plat/amlogic/gxbb/platform.mk b/plat/amlogic/gxbb/platform.mk
index 59c4f3d..57167b0 100644
--- a/plat/amlogic/gxbb/platform.mk
+++ b/plat/amlogic/gxbb/platform.mk
@@ -32,6 +32,7 @@
 				${AML_PLAT_COMMON}/aml_sip_svc.c		\
 				${AML_PLAT_COMMON}/aml_thermal.c		\
 				${AML_PLAT_COMMON}/aml_topology.c		\
+				${AML_PLAT_COMMON}/aml_console.c		\
 				${XLAT_TABLES_LIB_SRCS}				\
 				${GIC_SOURCES}