[U-Boot] CONFIG_ENV_IS_IN_UBI not working nicely with CONFIG_SPI_FLASH_MTD

[Edward Wingate]

I have been using u-boot with CONFIG_SPI_FLASH_MTD.  This has allowed
me to use MTD/UBI/UBIFS with SPI flash.  I now want to use
CONFIG_ENV_IS_IN_UBI, but after enabling this, u-boot can't read the
environment on start-up:

===
U-Boot 2015.07 (Sep 24 2015 - 17:10:41 -0700)

Model: Zynq Zed Development Board
I2C:   ready
DRAM:  ECC disabled 512 MiB
MMC:   zynq_sdhci: 0
Device nor0 not found!
Error initializing mtdparts!

** Cannot find mtd partition "uboot-env-itb"
Using default environment
===

"mtdparts" and "saveenv" do not work until after I do "sf probe".

I'm using u-boot on a Zynq 7020 SoC.  Can someone help me with what sf
probe-equivalent function call to make and where?  I'm guessing in
board_init_f() or board_init_r()?

Thanks for your help.