SPDX-License-Identifier: clean up license header

This patch cleans up license header in these files:
	board/freescale/p1022ds/spl.c
	drivers/mmc/fsl_esdhc_spl.c
	drivers/mtd/spi/fsl_espi_spl.c

Signed-off-by: York Sun <yorksun@freescale.com>

board/freescale/p1022ds/spl.c

 /*
  * Copyright 2013 Freescale Semiconductor, Inc.
  *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- *
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
- *
+ * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>

drivers/mmc/fsl_esdhc_spl.c

 /*
  * Copyright 2013 Freescale Semiconductor, Inc.
  *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- *
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
- *
+ * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>

drivers/mtd/spi/fsl_espi_spl.c

 /*
  * Copyright 2013 Freescale Semiconductor, Inc.
  *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- *
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
- *
+ * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>