Don't use "+=" operator in ARMv7-M.ld.sh
Don't use "+=" operator in ARMv7-M.ld.sh

This operator is a new bash extension, not supported by older versions
or other shells.
DISTORTEC/distortos,DISTORTEC/distortos,CezaryGapinski/distortos,DISTORTEC/distortos,jasmin-j/distortos,jasmin-j/distortos,DISTORTEC/distortos,CezaryGapinski/distortos,CezaryGapinski/distortos,CezaryGapinski/distortos,jasmin-j/distortos,CezaryGapinski/distortos,jasmin-j/distortos,jasmin-j/distortos