lib: correct description of CONFIG_SYS_FDT_PAD

CONFIG_SYS_FDT_PAD defines the number of unused bytes added to a
device-tree and not the total size.

Fixes: 40ed7be4af52 ("Convert CONFIG_SYS_FDT_PAD to Kconfig")
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
1 file changed