stm32mp15: deactivate CONFIG_SCMI_AGENT_MAILBOX

Deactivate the SCMI agent mailbox which is not used on STM32MP15
platforms.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Acked-by: Etienne Carriere <etienne.carriere@linaro.org>
2 files changed