ath79: remove redundant BLOCKSIZE of 64k from devices

BLOCKSIZE = 64k is set in Device/Default, i.e. global default on
the target.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

target/linux/ath79/image/generic.mk

@@ -1705,7 +1705,6 @@ define Device/openmesh_common_64k
   DEVICE_VENDOR := OpenMesh
   DEVICE_PACKAGES := uboot-envtools
   IMAGE_SIZE := 7808k
-  BLOCKSIZE := 64k
   OPENMESH_CE_TYPE :=
   KERNEL := kernel-bin | append-dtb | lzma | uImage lzma | \
 	pad-to $$(BLOCKSIZE)
@@ -1978,7 +1977,6 @@ define Device/plasmacloud_pa300-common
   DEVICE_VENDOR := Plasma Cloud
   DEVICE_PACKAGES := uboot-envtools
   IMAGE_SIZE := 7168k
-  BLOCKSIZE := 64k
   IMAGES += factory.bin
   KERNEL := kernel-bin | append-dtb | lzma | uImage lzma | pad-to $$(BLOCKSIZE)
   IMAGE/factory.bin := append-rootfs | pad-rootfs | openmesh-image ce_type=PA300

target/linux/ath79/image/nand.mk

@@ -102,7 +102,6 @@ TARGET_DEVICES += glinet_gl-ar300m-nand
 define Device/glinet_gl-ar300m-nor
   $(Device/glinet_gl-ar300m-common-nand)
   DEVICE_VARIANT := NOR
-  BLOCKSIZE := 64k
   SUPPORTED_DEVICES += glinet,gl-ar300m-nand gl-ar300m
 endef
 TARGET_DEVICES += glinet_gl-ar300m-nor
@@ -128,7 +127,6 @@ TARGET_DEVICES += glinet_gl-ar750s-nor-nand
 define Device/glinet_gl-ar750s-nor
   $(Device/glinet_gl-ar750s-common)
   DEVICE_VARIANT := NOR
-  BLOCKSIZE := 64k
   SUPPORTED_DEVICES += gl-ar750s glinet,gl-ar750s glinet,gl-ar750s-nor-nand
 endef
 TARGET_DEVICES += glinet_gl-ar750s-nor