arch: Add support for Atmel SAM E70 SoC configuration at boot

Added support for early SoC configuration which does not belong
conceptually to system initialization. ERASE, JTAG TDI pins are
currently configured here.

Tested on Atmel SMART SAM E70 Xplained board

Origin: Original

Jira: ZEP-978
Change-Id: Id51adddb4c7cce22907af214461d75db83df129a
Signed-off-by: Piotr Mienkowski <piotr.mienkowski@gmail.com>