feat(plat/st): add STM32MP_UART_PROGRAMMER target

Handle boot from UART with STM32CubeProgammer based on mmap io
for STM32MP15.

Depends-On: Iba84e8dfd67b9f30416efb0f6778e48ba1f75dad
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Change-Id: Ibd719dd46a11da78633728675ef6639635b6cf67
diff --git a/plat/st/common/include/stm32mp_common.h b/plat/st/common/include/stm32mp_common.h
index 8a5fe48..6183964 100644
--- a/plat/st/common/include/stm32mp_common.h
+++ b/plat/st/common/include/stm32mp_common.h
@@ -48,6 +48,11 @@
 uint32_t stm32_iwdg_shadow_update(uint32_t iwdg_inst, uint32_t flags);
 #endif
 
+#if STM32MP_UART_PROGRAMMER
+/* Get the UART address from its instance number */
+uintptr_t get_uart_address(uint32_t instance_nb);
+#endif
+
 /*
  * Platform util functions for the GPIO driver
  * @bank: Target GPIO bank ID as per DT bindings