stm32mp: add support of STM32MP15x Rev.Y

Add support of STM32MP15x Rev.Y for the Silicon revision REV_ID = 0x2003.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
diff --git a/arch/arm/mach-stm32mp/stm32mp15x.c b/arch/arm/mach-stm32mp/stm32mp15x.c
index 660c907..afc56b0 100644
--- a/arch/arm/mach-stm32mp/stm32mp15x.c
+++ b/arch/arm/mach-stm32mp/stm32mp15x.c
@@ -266,7 +266,7 @@
 };
 
 static const char * const soc_pkg[] = { "??", "AD", "AC", "AB", "AA" };
-static const char * const soc_rev[] = { "?", "A", "B", "Z" };
+static const char * const soc_rev[] = { "?", "A", "B", "Z", "Y"};
 
 static void get_cpu_string_offsets(unsigned int *type, unsigned int *pkg,
 				   unsigned int *rev)
@@ -307,6 +307,9 @@
 	case CPU_REV2_1:
 		*rev = 3;
 		break;
+	case CPU_REV2_2:
+		*rev = 4;
+		break;
 	default:
 		*rev = 0;
 		break;