configs: iot2050: Disable CONFIG_CONSOLE_MUX

We only have serial as console option, and leaving this on turns on
SYS_CONSOLE_IS_IN_ENV which is also not true for these devices, leaving
an ugly

In:    No input devices available!
Out:   No output devices available!
Err:   No error devices available!

behind.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
diff --git a/configs/iot2050_defconfig b/configs/iot2050_defconfig
index bcbaa92..4fc3bcb 100644
--- a/configs/iot2050_defconfig
+++ b/configs/iot2050_defconfig
@@ -18,7 +18,6 @@
 CONFIG_SPL_DM_SPI=y
 CONFIG_DEFAULT_DEVICE_TREE="k3-am6528-iot2050-basic"
 CONFIG_SPL_TEXT_BASE=0x80080000
-CONFIG_SYS_PROMPT="IOT2050> "
 CONFIG_OF_LIBFDT_OVERLAY=y
 CONFIG_DM_RESET=y
 CONFIG_SPL_SERIAL=y
@@ -41,7 +40,6 @@
 CONFIG_AUTOBOOT_PROMPT="Hit SPACE to stop autoboot in %d seconds...\n"
 CONFIG_AUTOBOOT_STOP_STR=" "
 CONFIG_BOOTCOMMAND="run start_watchdog; run distro_bootcmd"
-CONFIG_CONSOLE_MUX=y
 # CONFIG_DISPLAY_CPUINFO is not set
 CONFIG_SPL_MAX_SIZE=0x58000
 CONFIG_SPL_HAS_BSS_LINKER_SECTION=y
@@ -62,6 +60,7 @@
 CONFIG_SPL_SPI_FLASH_SFDP_SUPPORT=y
 CONFIG_SPL_SPI_LOAD=y
 CONFIG_SYS_SPI_U_BOOT_OFFS=0x380000
+CONFIG_SYS_PROMPT="IOT2050> "
 CONFIG_SYS_MAXARGS=64
 CONFIG_SYS_PBSIZE=1050
 CONFIG_CMD_ASKENV=y