doc: Switch to MSYS2's dtc package
doc: Switch to MSYS2's dtc package

After Andy Gross submitted a package for the Device Tree Compiler
(dtc), and it has now become available on the MSYS2 package
repository, it's no longer needed for the user to manually compile
the DTC.

Signed-off-by: Carles Cufi <853081dc8dca4fe6a7e3c984752718b5db36e060@nordicsemi.no>

punitvara/zephyr,fbsder/zephyr,zephyriot/zephyr,Vudentz/zephyr,aceofall/zephyr-iotos,ldts/zephyr,aceofall/zephyr-iotos,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,kraj/zephyr,explora26/zephyr,mbolivar/zephyr,nashif/zephyr,punitvara/zephyr,punitvara/zephyr,explora26/zephyr,ldts/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,ldts/zephyr,runchip/zephyr-cc3220,nashif/zephyr,aceofall/zephyr-iotos,galak/zephyr,zephyriot/zephyr,GiulianoFranchetto/zephyr,runchip/zephyr-cc3220,finikorg/zephyr,galak/zephyr,nashif/zephyr,ldts/zephyr,kraj/zephyr,zephyriot/zephyr,fbsder/zephyr,kraj/zephyr,rsalveti/zephyr,fbsder/zephyr,explora26/zephyr,ldts/zephyr,rsalveti/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,rsalveti/zephyr,kraj/zephyr,punitvara/zephyr,finikorg/zephyr,runchip/zephyr-cc3220,finikorg/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,zephyriot/zephyr,nashif/zephyr,fbsder/zephyr,GiulianoFranchetto/zephyr,aceofall/zephyr-iotos,mbolivar/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,Vudentz/zephyr,Vudentz/zephyr,galak/zephyr,mbolivar/zephyr,galak/zephyr,explora26/zephyr,mbolivar/zephyr,Vudentz/zephyr,fbsder/zephyr,finikorg/zephyr,explora26/zephyr,runchip/zephyr-cc3220,mbolivar/zephyr,kraj/zephyr,aceofall/zephyr-iotos,runchip/zephyr-cc3220,GiulianoFranchetto/zephyr,zephyriot/zephyr,zephyrproject-rtos/zephyr,rsalveti/zephyr,punitvara/zephyr,rsalveti/zephyr,galak/zephyr