The currently supported SAM0 MCUs (samd21, saml21, saml1x) share the same
Timer peripheral, yet each of them carries it's own copy of the Timer
driver.
This introduces a new timer driver that is common for all sam0 MCUs and
uses structs for configuration instead of defines.
The following features were tested (briefly):
* UART (the first)
* I2C using a BMP180 on a SODAQ TPH board
* SPI0, connected to the on-board serial data flash (only DevID was read
using the periph_spi test program)
* xtimer is working (it's the same code as in samr21)
boards/sodaq-autonomo: Disable the "big" unittests because it does not fit