baremetal: Add IAR Renesas RX toolchain support
baremetal: Add IAR Renesas RX toolchain support

This commit adds a basic support of the IAR Embedded Workbench
toolchain for the Renesas RX processors family:

* https://www.renesas.com/us/en/products/microcontrollers-microprocessors/rx.html

Change-Id: I68d43eed4d89a5921eb55b56fdd3380b59c56054
Reviewed-by: Christian Kandeler <3aa99dcdd3f0cac61fb81c2a11771c0cc2497607@qt.io>
Reviewed-by: Ivan Komissarov <96f14e4d07227e958f51f7d2898113639e9498d9@gmail.com>

qtproject/qt-labs-qbs,qt-labs/qbs,qt-labs/qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qt-labs/qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qtproject/qt-labs-qbs