drivers: move scmi-msg out of st

Make the scmi-msg driver reused by others.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Change-Id: I5bc35fd4dab70f45c09b8aab65af4209cf23b124
diff --git a/plat/st/stm32mp1/stm32mp1_scmi.c b/plat/st/stm32mp1/stm32mp1_scmi.c
index 80faf0c..6d60bd4 100644
--- a/plat/st/stm32mp1/stm32mp1_scmi.c
+++ b/plat/st/stm32mp1/stm32mp1_scmi.c
@@ -8,8 +8,8 @@
 
 #include <platform_def.h>
 
-#include <drivers/st/scmi-msg.h>
-#include <drivers/st/scmi.h>
+#include <drivers/scmi-msg.h>
+#include <drivers/scmi.h>
 #include <drivers/st/stm32mp1_clk.h>
 #include <drivers/st/stm32mp_reset.h>
 #include <dt-bindings/clock/stm32mp1-clks.h>