arm: am437x: cm-t43: define prompt

Define prompt for cm-t43.

Cc: Tom Rini <trini@konsulko.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/cm_t43_defconfig b/configs/cm_t43_defconfig
index 672117a..d1da759 100644
--- a/configs/cm_t43_defconfig
+++ b/configs/cm_t43_defconfig
@@ -2,6 +2,7 @@
 CONFIG_TARGET_CM_T43=y
 CONFIG_DM_GPIO=y
 CONFIG_SPL=y
+CONFIG_SYS_PROMPT="CM-T43 # "
 # CONFIG_CMD_FLASH is not set
 CONFIG_CMD_SF=y
 CONFIG_CMD_USB=y