arm-bsp: musca-b1: Add Zephyr support

Zephyr supports Musca B1, and QEMU has an emulated Musca B1 board.  Add
the relevant parts to get this compiling with meta-zephyr and (in
theory) run QEMU.

Change-Id: I9af4aea03e31e96f8eee17f44913e747b1241891
Signed-off-by: Jon Mason <jon.mason@arm.com>

meta-arm-bsp/documentation/musca-b1.md

@@ -0,0 +1,26 @@
+# Musca B1
+
+## Overview
+For a description of the hardware, go to
+https://developer.arm.com/tools-and-software/development-boards/iot-test-chips-and-boards/musca-b-test-chip-board
+
+For current supported hardware by Zephyr, go to
+https://docs.zephyrproject.org/2.3.0/boards/arm/v2m_musca/doc/index.html
+
+For emulated hardware, go to
+https://www.qemu.org/docs/master/system/arm/musca.html
+
+## Building
+In the local.conf file, MACHINE should be set as follows:
+MACHINE ?= "musca-b1"
+
+To build for Zephyr:
+```bash$ bitbake-layers layerindex-fetch meta-zephyr```
+```bash$ bitbake zephyr-philosophers```
+
+To build the trusted firmware-m (and not Zephyr):
+```bash$ bitbake trusted-frimware-m```
+
+## Running
+To run Zephyr on the QEMU based machine, execute the following command
+```bash$ runqemu qemu-musca-b1```