Build system: Fix "dd: invalid number `0x800000'"

dd doesn't recognise hex number. the commit introducing this:
f21b657 build system: improve portability by not relying on extraordinary dd options

Change-Id: Ie0df3eb00fa2ba5d7bbb8218e24b864cbdd07c3a
Signed-off-by: WANG Siyuan <SiYuan.Wang@amd.com>
Signed-off-by: WANG Siyuan <wangsiyuanbuaa@gmail.com>
Reviewed-on: http://review.coreboot.org/9944
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
1 file changed