board: tegra30: switch to button cmd

Use recently added ability to assign commands to buttons via env.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
diff --git a/configs/grouper_common_defconfig b/configs/grouper_common_defconfig
index 05207c8..001f5b8 100644
--- a/configs/grouper_common_defconfig
+++ b/configs/grouper_common_defconfig
@@ -14,12 +14,13 @@
 CONFIG_TARGET_GROUPER=y
 CONFIG_CMD_EBTUPDATE=y
 CONFIG_SYS_LOAD_ADDR=0x82000000
+CONFIG_BUTTON_CMD=y
 CONFIG_BOOTDELAY=0
 CONFIG_AUTOBOOT_KEYED=y
 CONFIG_AUTOBOOT_KEYED_CTRLC=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_OF_SYSTEM_SETUP=y
-CONFIG_BOOTCOMMAND="if run check_button; then bootmenu; fi; bootflow scan; poweroff;"
+CONFIG_BOOTCOMMAND="bootflow scan; poweroff"
 CONFIG_SYS_PBSIZE=2084
 CONFIG_SPL_FOOTPRINT_LIMIT=y
 CONFIG_SPL_MAX_FOOTPRINT=0x8000