refactor(st): rename PLAT_NB_FIXED_REGS

Rename PLAT_NB_FIXED_REGS to PLAT_NB_FIXED_REGUS.
This avoids confusion with regulators and registers.

Signed-off-by: Pascal Paillet <p.paillet@st.com>
Change-Id: Idb2de7204fe978ffcdd729e6cbe453e85fd089b5
diff --git a/plat/st/stm32mp1/stm32mp1_def.h b/plat/st/stm32mp1/stm32mp1_def.h
index c5e1b96..0fa6c73 100644
--- a/plat/st/stm32mp1/stm32mp1_def.h
+++ b/plat/st/stm32mp1/stm32mp1_def.h
@@ -634,7 +634,7 @@
 /* 3 PWR + 1 VREFBUF + 14 PMIC regulators + 1 FIXED */
 #define PLAT_NB_RDEVS			U(19)
 /* 2 FIXED */
-#define PLAT_NB_FIXED_REGS		U(2)
+#define PLAT_NB_FIXED_REGUS		U(2)
 
 /*******************************************************************************
  * Device Tree defines