ARM: dts: omap3-evm: Enable DM and devicetree for TMDSEVM{3530, 3730}

This commit updates the configuration files needed to support OF_CONTROL
on the OMAP3 EVM baseboard.

Additionally:
- CONFIG_SYS_THUMB_BUILD is enabled
- CONFIG_SPL_ENV_SUPPORT is enabled

Tested using GCC 7.2.0 [--with-float=hard --with-mode=thumb].

Signed-off-by: Derald D. Woods <woods.technical@gmail.com>
diff --git a/arch/arm/mach-omap2/omap3/Kconfig b/arch/arm/mach-omap2/omap3/Kconfig
index 4dbf9a2..6d714f6 100644
--- a/arch/arm/mach-omap2/omap3/Kconfig
+++ b/arch/arm/mach-omap2/omap3/Kconfig
@@ -61,6 +61,10 @@
 
 config TARGET_OMAP3_EVM
 	bool "TI OMAP3 EVM"
+	select DM
+	select DM_SERIAL
+	select DM_GPIO
+	select OMAP3_GPIO_3
 
 config TARGET_OMAP3_IGEP00X0
 	bool "IGEP"