toradex: apalis/colibri imx6: Select correct DTB for SoM v1.2+

When "fdtfile" is not set, use the "variant" environment variable to
select the correct DTB.

Apalis/Colibri iMX6 V1.2 replaced the STMPE811 ADC/Touch controller
which is EOL with the TLA2024 ADC and AD7879 touch controller. They thus
require a different DTB, which we can easily select with the variant env
variable.

Signed-off-by: Ernest Van Hoecke <ernest.vanhoecke@toradex.com>
Reviewed-by: Francesco Dolcini <francesco.dolcini@toradex.com>
diff --git a/configs/apalis_imx6_defconfig b/configs/apalis_imx6_defconfig
index a3f65c5..f51386d 100644
--- a/configs/apalis_imx6_defconfig
+++ b/configs/apalis_imx6_defconfig
@@ -31,7 +31,7 @@
 CONFIG_BOOTDELAY=1
 CONFIG_BOOTCOMMAND="run distro_bootcmd; usb start; setenv stdout serial,vidconsole; setenv stdin serial,usbkbd"
 CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="test -n ${fdtfile} || setenv fdtfile imx6q-apalis-${fdt_board}.dtb"
+CONFIG_PREBOOT="test -n ${fdtfile} || setenv fdtfile imx6q-apalis${variant}-${fdt_board}.dtb"
 CONFIG_SYS_CBSIZE=1024
 CONFIG_SYS_PBSIZE=1055
 CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE=y
diff --git a/configs/colibri_imx6_defconfig b/configs/colibri_imx6_defconfig
index 4c6ba80..9fc844b 100644
--- a/configs/colibri_imx6_defconfig
+++ b/configs/colibri_imx6_defconfig
@@ -30,7 +30,7 @@
 CONFIG_BOOTDELAY=1
 CONFIG_BOOTCOMMAND="run distro_bootcmd; usb start; setenv stdout serial,vidconsole; setenv stdin serial,usbkbd"
 CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="test -n ${fdtfile} || setenv fdtfile imx6dl-colibri-${fdt_board}.dtb"
+CONFIG_PREBOOT="test -n ${fdtfile} || setenv fdtfile imx6dl-colibri${variant}-${fdt_board}.dtb"
 CONFIG_SYS_CBSIZE=1024
 CONFIG_SYS_PBSIZE=1056
 CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE=y