kw41z: Add kw41z SoC

Adds initial support for the kw41z SoC. This is the first SoC in the
Kinetis W (wireless connectivity) series added to Zephyr. The kw41z
integrates a 2.4 GHz radio transceiver, BLE link layer hardware, and an
802.15.4 packet processor with an ARM Cortex M0+. It has 512 KB flash,
128 KB SRAM, and can run the system clock at up to 48 MHz.

This SoC currently has mcux shim drivers for lpuart (serial), gpio,
pinmux, i2c, and flash.

Jira: ZEP-1389
Change-Id: I8cff6d203867ba3ace7e05c36441dc8f3cbca8d8
Signed-off-by: Maureen Helm <maureen.helm@nxp.com>

arch/arm/soc/nxp_kinetis/kwx/Kconfig.soc

@@ -0,0 +1,39 @@
+# Kconfig - Kinetis KWx MCU series
+#
+# Copyright (c) 2017, NXP
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+choice
+prompt "Kinetis KWx MCU Selection"
+depends on SOC_SERIES_KINETIS_KWX
+
+config SOC_MKW41Z4
+	bool "SOC_MKW41Z4"
+	select CPU_CORTEX_M0PLUS
+	select HAS_MCUX
+	select HAS_OSC
+	select HAS_MCG
+	select HAS_LPUART
+
+endchoice
+
+if SOC_SERIES_KINETIS_KWX
+
+config SOC_PART_NUMBER_MKW41Z256VHT4
+	bool
+
+config SOC_PART_NUMBER_MKW41Z512VHT4
+	bool
+
+config SOC_PART_NUMBER_KINETIS_KWX
+	string
+	default "MKW41Z256VHT4" if SOC_PART_NUMBER_MKW41Z256VHT4
+	default "MKW41Z512VHT4" if SOC_PART_NUMBER_MKW41Z512VHT4
+	help
+	This string holds the full part number of the SoC. It is a hidden option
+	that you should not set directly. The part number selection choice defines
+	the default value for this string.
+
+endif # SOC_SERIES_KINETIS_KWX