sam3n port: revert to our custom made register definition includes.

sam3n port: revert to our custom made register definition includes.

SAM3 peripherals are very similar to SAM7 one.  To allow reuse of SAM7
drivers we need to use same register definitions.  Atmel supplied
include file defines register offsets with the bare register name
(i.e. PIO_PDR) and access register macro with the REG_ prefix.
Instead the SAM7 tree defines offsets with _OFF suffix and access
register macros with the bare register name.  Moreover register
bits are defined as bit numbers, i.e. when using them on registers
the BV() macro is required.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@4432 38d2e660-2303-0410-9eaa-f027e97ec537