Merge pull request #10653 from dylad/pr/saml1x_support

boards/common/saml1x/Makefile

boards/common/saml1x/Makefile.dep

boards/common/saml1x/Makefile.features

boards/common/saml1x/Makefile.include

boards/common/saml1x/board.c

boards/common/saml1x/include/board.h

boards/common/saml1x/include/gpio_params.h

boards/common/saml1x/include/periph_conf.h

boards/saml10-xpro/Makefile

boards/saml10-xpro/Makefile.dep

boards/saml10-xpro/Makefile.features

boards/saml10-xpro/Makefile.include

boards/saml10-xpro/doc.txt

boards/saml11-xpro/Makefile

boards/saml11-xpro/Makefile.dep

boards/saml11-xpro/Makefile.features

boards/saml11-xpro/Makefile.include

boards/saml11-xpro/doc.txt

cpu/cortexm_common/cortexm_init.c

cpu/cortexm_common/mpu.c