board: stemmy: Add basic Fastboot support

Make use of the new drivers for ARM U8500 introduced in the U-Boot
2021.10 merge window by adding basic support for USB Fastboot with
the "stemmy" board. As a first step this will always boot directly
into USB Fastboot for now with the console displayed on the screen
to make that obvious.

Samsung uses quite strange GPT partition labels on these boards,
so also add a bunch of fastboot_partition_alias_* to make this more
easy to use.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
diff --git a/configs/stemmy_defconfig b/configs/stemmy_defconfig
index c026081..77bc5c7 100644
--- a/configs/stemmy_defconfig
+++ b/configs/stemmy_defconfig
@@ -6,6 +6,8 @@
 CONFIG_SYS_MALLOC_LEN=0x0200000
 CONFIG_DEFAULT_DEVICE_TREE="ste-ux500-samsung-stemmy"
 CONFIG_SYS_LOAD_ADDR=0x100000
+CONFIG_USE_BOOTCOMMAND=y
+CONFIG_BOOTCOMMAND="run fastbootcmd"
 CONFIG_SYS_CONSOLE_INFO_QUIET=y
 CONFIG_HUSH_PARSER=y
 CONFIG_CMD_CONFIG=y
@@ -17,5 +19,17 @@
 CONFIG_CMD_GETTIME=y
 CONFIG_EFI_PARTITION=y
 # CONFIG_NET is not set
+CONFIG_USB_FUNCTION_FASTBOOT=y
+CONFIG_FASTBOOT_BUF_ADDR=0x18100000
+CONFIG_FASTBOOT_FLASH=y
+CONFIG_FASTBOOT_FLASH_MMC_DEV=0
 # CONFIG_MMC_HW_PARTITIONING is not set
+CONFIG_USB=y
+CONFIG_USB_MUSB_GADGET=y
+CONFIG_USB_GADGET=y
+CONFIG_USB_GADGET_VENDOR_NUM=0x04e8
+CONFIG_USB_GADGET_PRODUCT_NUM=0x685d
+CONFIG_DM_VIDEO=y
+CONFIG_SYS_WHITE_ON_BLACK=y
+CONFIG_VIDEO_MCDE_SIMPLE=y
 # CONFIG_EFI_LOADER is not set