test: cmd: fdt: fix chosen test for DM_RNG

test: cmd: fdt: fix chosen test for DM_RNG

Now that kaslr-seed is automatically added to the chosen node if DM_RNG
is enabled, adjust the test to expect this.

Take care not to expect kaslr-seed for CONFIG_MEASURED_BOOT and
CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT as we do not add it for those.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Cc: Michal Simek <michal.simek@amd.com>
Cc: Andy Yan <andy.yan@rock-chips.com>
Cc: Akash Gajjar <gajjar04akash@gmail.com>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Simon Glass <sjg@chromium.org>
Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
Cc: Patrice Chotard <patrice.chotard@foss.st.com>
Cc: Devarsh Thakkar <devarsht@ti.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Tom Rini <trini@konsulko.com>
Cc: Chris Morgan <macromorgan@hotmail.com>