make: add gpio feature
tests/driver_pir: set default GPIO
Merge pull request #1765 from LudwigOrtmann/feature_gpio

make: add gpio feature
drivers - spi: extended low-level spi driver interface
cpu - stm32fx: adapt spi drivers to interface extension
drivers - cc110x_v2: Initial import of cc110x_v2 driver
boards - msbiot: prepare msbiot for new cc110x driver
cpu - stm32f4: define necessary buffer sizes
support new cc110x_v2 globally
sys - transceiver: make transceiver ready for cc110x_v2
are those necessary/useless/valid
boards - msbiot: add transceiver as feature