brcm63xx: fix A4001N image padding size

When r42245 moved A4001N to DT based detection the image padding size
was accidentally increased from 4 to 8 MiB. This made images unflashable
on these devices.

Fixes #19836.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@45945 3c298f89-4303-0410-b956-a3cf2f4a3e73

target/linux/brcm63xx/image/Makefile

@@ -291,7 +291,7 @@ $(eval $(call ImageDTB,CFEDTB,96368MVNgr,96368MVNgr-generic,bcm96368MVNgr,96368M
 $(eval $(call ImageDTB,CFEDTB,96368MVWG,96368MVWG-generic,bcm96368MVWG,96368MVWG,6368))
 
 # ADB P.DG A4001N
-$(eval $(call ImageDTB,CFEDTB,A4001N,A4001N,a4001n,96328dg2x2,6328,--pad 8))
+$(eval $(call ImageDTB,CFEDTB,A4001N,A4001N,a4001n,96328dg2x2,6328,--pad 4))
 # ADB P.DG A4001N1
 $(eval $(call ImageDTB,CFEDTB,A4001N1,A4001N1,a4001n1,963281T_TEF,6328,--pad 8))
 # Alcatel RG100A