refactor(stm32mp15-fdts): remove unused secure-status properties

For peripheral where both status and secure-status are set to okay,
the function fdt_get_status() returns the same status (DT_SHARED) if
secure-status property is omitted. This secure-status property can then
be removed in boards DT files for iwdg nodes.

Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Change-Id: I9f9360842d4d41288db0cf1b92063f347c72d137
4 files changed