M4PROJECTS-STM32MP1: fix board pattern and installation path

Signed-off-by: Lionel VITTE <lionel.vitte@st.com>
Change-Id: Ic28d02e3043d838c1c3848331e38b67472feac6e

recipes-extended/m4projects/files/shutdown-stm32mp1-m4.sh

@@ -1,7 +1,7 @@
 #!/bin/sh -
 
 # test if we are a stm32mp1
-if ! $(grep -q "stm32mp157[acdf]-dk\|ev" /proc/device-tree/compatible) ;
+if ! $(grep -q "stm32mp157[acdf]-\(dk\|ev\)" /proc/device-tree/compatible) ;
 then
     exit 0
 fi