doc: output alphabetic Kconfig options index
tests: Add PWM driver api test
tests: add zephyr alerts test case
doc: Add environment variables to getting_started.rst
docs: remove usage of ARCH=arm
checkpatch: update with latest checkpatch from the linux kernel
tests/crypto/test_mbedtls: increase timeouts for HW
tests/kernel/test_{fifo,lifo,stack}: filter unified kernel for small memory