refactor(st): move some storage definitions to common part

Those storage macros are common to all STM32MPU chips, move them to
plat/st/common/include/stm32mp_io_storage.h

Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Change-Id: Id20ec00ba65edf9ec7a3a89adfda307c954c3cb6
diff --git a/plat/st/common/include/stm32mp_common.h b/plat/st/common/include/stm32mp_common.h
index bb3401f..e334f22 100644
--- a/plat/st/common/include/stm32mp_common.h
+++ b/plat/st/common/include/stm32mp_common.h
@@ -14,6 +14,9 @@
 #define JEDEC_ST_BKID U(0x0)
 #define JEDEC_ST_MFID U(0x20)
 
+/* FWU configuration (max supported value is 15) */
+#define FWU_MAX_TRIAL_REBOOT		U(3)
+
 /* Functions to save and get boot context address given by ROM code */
 void stm32mp_save_boot_ctx_address(uintptr_t address);
 uintptr_t stm32mp_get_boot_ctx_address(void);