global: Remove leading/trailing blank lines in files

Remove leading/trailing blank lines in .c, .h, .py, .rst, .yml, and
.yaml files.

Will avoid failures with the new CI test in
https://github.com/zephyrproject-rtos/ci-tools/pull/112

, though it only
checks changed files.

Move the 'target-notes' target in boards/xtensa/odroid_go/doc/index.rst
to get rid of the trailing blank line there. It was probably misplaced.

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>