Porting BareBox to Variscite iMX6 SOM

[Michael Burkey]

Thank you Sascha for the additional information in your earlier post!

Your comments on the imx-image method got me looking at the menuconfig
options and I located a simple mistake I had made when changing other
options (while manually editing some files, I had somehow managed to
inadvertently disable the "support internal boot" option).

After fixing this, everything now works as I would expect.

So, I now have the Variscite iMX6 SOM booted directly from SD to the
BareBox shell on UART1.

Now I just have to start pulling in all the other devices and getting
them configured properly!