Freedom kl46z (first tests)

Hello,

I added ARM (KEIL) support, run some tests with GCC/KEIL. However,  the testing phase is not completed (SPI failed, and others which don't contain KL46Z defines were not tested yet).

I prefer to merge this as it is, not having much time in the following days for this task. Anybody can take over testing and correcting the rest of HAL. When I allocate some free time, I'll continue. I'll keep the issue for this task as opened.



Regards,
0xc0170