am437x: Add am437x_gp_evm_defconfig using CONFIG_DM

Import various DT files for am4372, an43xx pinctrl and
am437x-gp-evm from Linux Kernel v4.2
Add config file for this board, enable DM, DM_GPIO, DM_SERIAL
and DM_MMC.

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>
diff --git a/configs/am437x_gp_evm_defconfig b/configs/am437x_gp_evm_defconfig
new file mode 100644
index 0000000..53fb0bf
--- /dev/null
+++ b/configs/am437x_gp_evm_defconfig
@@ -0,0 +1,17 @@
+CONFIG_ARM=y
+CONFIG_TARGET_AM43XX_EVM=y
+CONFIG_DEFAULT_DEVICE_TREE="am437x-gp-evm"
+CONFIG_SPL=y
+CONFIG_SPL_STACK_R=y
+CONFIG_SPL_STACK_R_ADDR=0x82000000
+CONFIG_SYS_EXTRA_OPTIONS="CONS_INDEX=1"
+# CONFIG_CMD_IMLS is not set
+# CONFIG_CMD_FLASH is not set
+# CONFIG_CMD_SETEXPR is not set
+CONFIG_OF_CONTROL=y
+CONFIG_SPL_DISABLE_OF_CONTROL=y
+CONFIG_DM=y
+CONFIG_SPI_FLASH=y
+CONFIG_DM_GPIO=y
+CONFIG_DM_SERIAL=y
+CONFIG_DM_MMC=y