west.yml: MCUBoot updated to support stm32 variants

Takes the mcu-tools/mcuboot#2399

Signed-off-by: Francois Ramu <francois.ramu@st.com>

Author: FRASTM

west.yml

@@ -310,7 +310,7 @@ manifest:
       groups:
         - crypto
     - name: mcuboot
-      revision: 461e060e8687c9a75074effcc61d7f68c5112cfd
+      revision: pull/2399/head
       path: bootloader/mcuboot
       groups:
         - bootloader