[U-Boot] Add mikroBUS flash click support to the imx7

[Angus Ainslie]

In-Reply-To: 


Add support for the "flash click" and probably other SPI mikroBUS click
boards on i.MX7 Sabre evaluation board.

 board/freescale/mx7dsabresd/mx7dsabresd.c |   24 ++++++++++++++++++++++++
 configs/mx7dsabresd_secure_defconfig      |    2 ++
 drivers/mtd/spi/sf_params.c               |    1 +
 include/configs/mx7dsabresd.h             |    4 ++++
 4 files changed, 31 insertions(+)