arm: soc: move arm SoCs to top-dir

Move the SoC outside of the architecture tree and put them at the same
level as boards and architectures allowing both SoCs and boards to be
maintained outside the tree.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

soc/arm/st_stm32/stm32f4/Kconfig.defconfig.stm32f412cg

@@ -0,0 +1,38 @@
+# Kconfig - ST STM32F412CG MCU configuration options
+#
+# Copyright (c) 2018, I-SENSE group of ICCS
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+if SOC_STM32F412CG
+
+config SOC
+	string
+	default "stm32f412cx"
+
+config NUM_IRQS
+	int
+	default 97
+
+if GPIO_STM32
+
+config GPIO_STM32_PORTD
+	default n
+
+config GPIO_STM32_PORTE
+	default n
+
+config GPIO_STM32_PORTH
+	default n
+
+endif # GPIO_STM32
+
+if ENTROPY_GENERATOR
+
+config ENTROPY_STM32_RNG
+	def_bool y
+
+endif # ENTROPY_GENERATOR
+
+endif # SOC_STM32F412CG