Prepare v2023.10-stm32mp-r1

Update version in Makefile to prepare the label v2023.10-stm32mp-r1
for OpenSTLinux V6.0.0

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Change-Id: I814ff40814416ffe85c029e1c18992b09a87f2f2

Author: Patrice Chotard

Makefile

@@ -3,7 +3,7 @@
 VERSION = 2023
 PATCHLEVEL = 10
 SUBLEVEL =
-EXTRAVERSION =
+EXTRAVERSION = -stm32mp-r1
 NAME =
 
 # *DOCUMENTATION*