Add board search strings for Zolertia devices

arch/platform/zoul/firefly-reva/Makefile.firefly-reva

-MOTELIST_ZOLERTIA = firefly
+MOTELIST_ZOLERTIA := Firefly
 BOARD_SOURCEFILES += board.c

arch/platform/zoul/firefly/Makefile.firefly

-MOTELIST_ZOLERTIA = firefly
+MOTELIST_ZOLERTIA := Firefly
 BOARD_SOURCEFILES += board.c

arch/platform/zoul/orion/Makefile.orion

-MOTELIST_ZOLERTIA = orion
+MOTELIST_ZOLERTIA := Orion
 MODULES += arch/dev/enc28j60
 CC2538_ENC28J60_ARCH ?= gpio
 ifeq ($(WITH_IP64),1)

arch/platform/zoul/remote-reva/Makefile.remote-reva

-MOTELIST_ZOLERTIA = remote
+MOTELIST_ZOLERTIA := RE-Mote
 BOARD_SOURCEFILES += board.c antenna-sw.c mmc-arch.c rtcc.c power-mgmt.c
 
 MODULES += os/lib/fs/fat os/lib/fs/fat/option arch/platform/zoul/fs/fat arch/dev/disk/mmc

arch/platform/zoul/remote-revb/Makefile.remote-revb

-MOTELIST_ZOLERTIA = remote
+MOTELIST_ZOLERTIA := RE-Mote
 BOARD_SOURCEFILES += board.c antenna-sw.c mmc-arch.c rtcc.c power-mgmt.c
 
 MODULES += os/lib/fs/fat os/lib/fs/fat/option arch/platform/zoul/fs/fat arch/dev/disk/mmc