fix(stm32mp2): set PLAT_MAX_PWR_LVL to one

Set maximum power level to 1 as power management isn't implemented yet.

Change-Id: I26cefbb5e199944d371bf06a76b2c41f73d38585
Signed-off-by: Maxime Méré <maxime.mere@foss.st.com>
diff --git a/plat/st/stm32mp2/include/platform_def.h b/plat/st/stm32mp2/include/platform_def.h
index b98b56d..e720c02 100644
--- a/plat/st/stm32mp2/include/platform_def.h
+++ b/plat/st/stm32mp2/include/platform_def.h
@@ -33,7 +33,7 @@
 #define PLATFORM_CORE_COUNT		U(2)
 #define PLATFORM_MAX_CPUS_PER_CLUSTER	U(2)
 
-#define PLAT_MAX_PWR_LVL		U(3)
+#define PLAT_MAX_PWR_LVL		U(1)
 #define PLAT_MIN_SUSPEND_PWR_LVL	U(2)
 #define PLAT_NUM_PWR_DOMAINS		U(6)