Add support for SAM4E (Baremetal example)

[chepo92]

Here I add a generic board with SAM4E (sam4e8e) mcu, and a working blink example, it can be reused for other SAM (like SAM3 from arduino DUE, and other SAM4 series: SAM4N SAM4L SAM4S) changing some defs and providing a linker script.

The example is baremetal, so no framework, no CMSIS (but used some definitions from there)

I might come with an arduino core port for this chip series later, if anyone willing to help or test just send a message