mediatek: image: don't use 'M' unit as dd may not support that

dd on Mac OS X apparently fails when using 'M' unit for bs.
dd: bs: illegal numeric value
Use 'k' unit instead for 'pad-to' to fix that.

Reported-by: Georgi Valkov <[email protected]>
Signed-off-by: Daniel Golle <[email protected]>

target/linux/mediatek/image/mt7622.mk

@@ -48,8 +48,8 @@ define Device/bananapi_bpi-r64
   IMAGES := sysupgrade.itb
   KERNEL_INITRAMFS_SUFFIX := -recovery.itb
   ARTIFACT/sdcard.img		:= mt7622-gpt sdmmc | pad-to 128k | mt7622-gpt emmc | pad-to 256k |\
-				   bl2 emmc-2ddr | pad-to 512k | bl2 sdmmc-2ddr | pad-to 1M | bl31-uboot bananapi_bpi-r64-emmc | pad-to 2M |\
-				   bl31-uboot bananapi_bpi-r64-sdmmc | pad-to 6M
+				   bl2 emmc-2ddr | pad-to 512k | bl2 sdmmc-2ddr | pad-to 1024k | bl31-uboot bananapi_bpi-r64-emmc | pad-to 2048k |\
+				   bl31-uboot bananapi_bpi-r64-sdmmc | pad-to 6144k
   KERNEL			:= kernel-bin | gzip
   KERNEL_INITRAMFS		:= kernel-bin | lzma | fit lzma $$(DTS_DIR)/$$(DEVICE_DTS).dtb with-initrd | pad-to 128k
   IMAGE/sysupgrade.itb		:= append-kernel | fit gzip $$(DTS_DIR)/$$(DEVICE_DTS).dtb external-static-with-rootfs | append-metadata