uboot-imx

ARM: rmobile: Ignore U-Boot env when started via JTAG on Porter

When U-Boot is started via JTAG, ignore the installed environment
as it may interfere with the recovery of the board.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>