In order to ease introduction of new STM32 MPUs platforms, a dedicated
ST sub-menu (and directory) is created.
The old page is kept, but with an orphan parameter to avoid build
issues with the docs, and to avoid listing it in the menu. It is
updated to just have links with the new pages.
A new page STM32 MPUs is created to group common options for all STM32
MPUs.
Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Change-Id: I799b57967d76a985835c7a3d9d6ab21beb44ba40
ce7f8044c7