ext: simplelink: Build files for the SimpleLink host driver and DPL.

This patch adds files to build the SimpleLink host driver
and its DPL port to Zephyr.

It disables the host driver build by default.

Signed-off-by: Gil Pitney <gil.pitney@linaro.org>
diff --git a/ext/hal/ti/simplelink/Kconfig b/ext/hal/ti/simplelink/Kconfig
index a7d7943..362b9aa 100644
--- a/ext/hal/ti/simplelink/Kconfig
+++ b/ext/hal/ti/simplelink/Kconfig
@@ -3,9 +3,15 @@
 config HAS_CC3220SDK
 	bool
 
-menuconfig CC3220SDK
-	bool "TI CC3220 SDK support"
+# Notes:
+# SimpleLink drivers require types (stdint.h) from NEWLIB_LIBC
+# Selecting ERRNO lets host driver use Zephyr's __errno
+config SIMPLELINK_HOST_DRIVER
+	bool "Build the SimpleLink WiFi Host Driver"
 	default n
 	depends on HAS_CC3220SDK
+	depends on MULTITHREADING
+	depends on NEWLIB_LIBC
+	select ERRNO
 	help
-	Build required peripheral driverlib files from the CC3220 SDK
+	Build the SimpleLink host driver