mainboard/*/*/Kconfig*: Remove leading blank lines from SPDX header

Change-Id: I7089b29e881d74d31477e2df1c5fa043fe353343
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41358
Reviewed-by: Wim Vervoorn <wvervoorn@eltan.com>
Reviewed-by: Frans Hendriks <fhendriks@eltan.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/biostar/a68n_5200/Kconfig

@@ -1,6 +1,3 @@
-#
-#
-#
 # SPDX-License-Identifier: GPL-2.0-only
 
 if BOARD_BIOSTAR_A68N5200

src/mainboard/biostar/am1ml/Kconfig

@@ -1,6 +1,3 @@
-#
-#
-#
 # SPDX-License-Identifier: GPL-2.0-only
 
 if BOARD_BIOSTAR_AM1ML