layerscape: define only one package for ls-rcw

We do not have to define package for each board, and
consider variant's building/installing.
It is easier to maintain ls-rcw with only one package
installing all boards RCW binaries as intermediate
files, each of which is just about hundreds of bytes.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>

target/linux/layerscape/image/armv7.mk

@@ -19,7 +19,7 @@ define Device/ls1021atwr
   DEVICE_VENDOR := NXP
   DEVICE_MODEL := TWR-LS1021A
   DEVICE_VARIANT := Default
-  DEVICE_PACKAGES += layerscape-rcw-ls1021atwr
+  DEVICE_PACKAGES += layerscape-rcw
   DEVICE_DTS := ls1021a-twr
   IMAGE/firmware.bin := \
     ls-clean | \