feat(stm32mp1): add a second fixed regulator

Increase the fixed regulator number that needs to be
2 for STM32MP13.

Signed-off-by: Lionel Debieve <lionel.debieve@foss.st.com>
Change-Id: Ica990fe9a6494b76aed763d2d353f5234fed7cea
diff --git a/plat/st/stm32mp1/stm32mp1_def.h b/plat/st/stm32mp1/stm32mp1_def.h
index d6e1788..080bf01 100644
--- a/plat/st/stm32mp1/stm32mp1_def.h
+++ b/plat/st/stm32mp1/stm32mp1_def.h
@@ -579,8 +579,8 @@
  ******************************************************************************/
 /* 3 PWR + 1 VREFBUF + 14 PMIC regulators + 1 FIXED */
 #define PLAT_NB_RDEVS			U(19)
-/* 1 FIXED */
-#define PLAT_NB_FIXED_REGS		U(1)
+/* 2 FIXED */
+#define PLAT_NB_FIXED_REGS		U(2)
 
 /*******************************************************************************
  * Device Tree defines