arm: apple: Do not list bootflows on boot

The bootflow list is only seen briefly and is probably more confusing
than helpful.

Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Reviewed-by: Mark Kettenis <kettenis@openbsd.org>

configs/apple_m1_defconfig

@@ -8,6 +8,7 @@ CONFIG_SYS_CBSIZE=256
 CONFIG_SYS_PBSIZE=276
 # CONFIG_DISPLAY_CPUINFO is not set
 CONFIG_DISPLAY_BOARDINFO_LATE=y
+CONFIG_BOOTCOMMAND="bootflow scan -b"
 CONFIG_BOARD_LATE_INIT=y
 CONFIG_CMD_SELECT_FONT=y
 # CONFIG_NET is not set