treewide: add missing commas to enums and struct definitions

treewide: add missing commas to enums and struct definitions

The code is not consistent with regard to following the last element in
enums and struct definitions with a comma. Unless the last element is
guaranteed not to change (e.g. '{ }', or NULL), follow it with a comma
treewide to avoid churn in git when adding new values.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>