atmel/ATSAMR21G18A: update to version 1.2 of SVD data
atmel/ATSAMR21G18A: update to version 1.2 of SVD data

Signed-off-by: Ron Evans <b937b287f61b7a223d4aac55072db1a5381d3bb3@hybridgroup.com>

posborne/cmsis-svd