stm32: remove dt-binding headers that are available upstream

Some dt-binding headers mask the upstream ones which can lead to build
failures, or worse: super weird bugs, if they get out of sync.

Remove these headers so our devicetree and binding headers will both be
in sync with upstream.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
12 files changed