ARM: mach-imx: Remove board entries in dt_board_compat

There is no need for adding board related entries into dt_board_compat.

Leave only the SoC entry.

This way we do not need to patch a C file when adding dt support for
a new board.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/mach-imx/imx51-dt.c

@@ -79,7 +79,6 @@ static struct sys_timer imx51_timer = {
 };
 
 static const char *imx51_dt_board_compat[] __initdata = {
-	"fsl,imx51-babbage",
 	"fsl,imx51",
 	NULL
 };

arch/arm/mach-imx/imx53-dt.c

@@ -105,10 +105,6 @@ static struct sys_timer imx53_timer = {
 };
 
 static const char *imx53_dt_board_compat[] __initdata = {
-	"fsl,imx53-ard",
-	"fsl,imx53-evk",
-	"fsl,imx53-qsb",
-	"fsl,imx53-smd",
 	"fsl,imx53",
 	NULL
 };

arch/arm/mach-imx/mach-imx6q.c

@@ -218,9 +218,6 @@ static struct sys_timer imx6q_timer = {
 };
 
 static const char *imx6q_dt_compat[] __initdata = {
-	"fsl,imx6q-arm2",
-	"fsl,imx6q-sabrelite",
-	"fsl,imx6q-sabresd",
 	"fsl,imx6q",
 	NULL,
 };