[PATCH] configs: stm32mp: force empty PREBOOT

[Patrick Delaunay]

This patch remove the default preboot command 'usb start' for
STMicroelectronics board. These command is added by the
commit 324d77998ed6 ("Define default CONFIG_PREBOOT with right config
option")' and commit 44758771eefb ("arm: move CONFIG_PREBOOT="usb start"
to KConfig").

The USB storage boot (not activated in stm32mp1.h) is correctly
managed by distro boot command 'usb_boot' (defined in
include/config_distro_bootcmd.h, it include 'usb start')
and USB keyboard is not supported in stm32mp15 defconfig.

So this patch avoids unnecessary USB initialization which slows
down the start-up:
  starting USB...
  Bus usbh-ehci at 5800d000: USB EHCI 1.00
  scanning bus usbh-ehci at 5800d000 for devices... 3 USB Device(s) found
         scanning usb for storage devices... 1 Storage Device(s) found

Cc: Peter Robinson <pbrobinson at gmail.com>
Cc: Jonas Smedegaard <dr at jones.dk>
Cc: Neil Armstrong <narmstrong at baylibre.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com>
---

 configs/stm32mp15_basic_defconfig   | 1 +
 configs/stm32mp15_trusted_defconfig | 1 +
 2 files changed, 2 insertions(+)

diff --git a/configs/stm32mp15_basic_defconfig b/configs/stm32mp15_basic_defconfig
index a8c4112dbe..f937a0278d 100644
--- a/configs/stm32mp15_basic_defconfig
+++ b/configs/stm32mp15_basic_defconfig
@@ -19,6 +19,7 @@ CONFIG_DEFAULT_DEVICE_TREE="stm32mp157c-ev1"
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_FIT=y
 CONFIG_BOOTCOMMAND="run bootcmd_stm32mp"
+CONFIG_PREBOOT=""
 CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION=y
 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION=3
diff --git a/configs/stm32mp15_trusted_defconfig b/configs/stm32mp15_trusted_defconfig
index 0792884a9d..b0be064cc3 100644
--- a/configs/stm32mp15_trusted_defconfig
+++ b/configs/stm32mp15_trusted_defconfig
@@ -12,6 +12,7 @@ CONFIG_DEFAULT_DEVICE_TREE="stm32mp157c-ev1"
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_FIT=y
 CONFIG_BOOTCOMMAND="run bootcmd_stm32mp"
+CONFIG_PREBOOT=""
 CONFIG_SYS_PROMPT="STM32MP> "
 CONFIG_CMD_ADTIMG=y
 # CONFIG_CMD_ELF is not set
-- 
2.17.1