uboot-imx

sandbox: config: Enable all SPI flash chips

Sandbox may as well support everything. This increases the amount of code
that is built/tested by sandbox, and also provides access to all the
supported SPI flash devices.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>