arm: sunxi: do not force USB for arch-sunxi

Currently, USB is forced-enabled for the sunxi familly, and there is no
way to disable it.

However, USB takes a long time to initiliase, delaying the boot by up to
5 seconds (without any USB device attached!). This is a very long delay,
especially in cases where USB booting is not wanted at all, and where
the device is expected to boot relatively often (even in production).

Change the way the dependencies are handled, by only forcibly selecting
USB when CONFIG_DISTRO_DEFAULTS ("defaults suitable for booting general
purpose Linux distributions") is set. This option defaults to y for the
sunxi familly, so the current default behaviour is kept unchanged. Users
interested in boot time and/or size will be able to disable this to
further disable USB.

With USB disabled, the time spent in U-Boot before handing control to
the Linux kernel is about 1s now, down from ~5s (Nanopi Neo, sunxi H3).

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Ian Campbell <ijc@hellion.org.uk>
Cc: Hans De Goede <hdegoede@redhat.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

arch/arm/Kconfig

@@ -556,22 +556,22 @@ config ARCH_SUNXI
 	bool "Support sunxi (Allwinner) SoCs"
 	select CMD_GPIO
 	select CMD_MMC if MMC
-	select CMD_USB
+	select CMD_USB if DISTRO_DEFAULTS
 	select DM
 	select DM_ETH
 	select DM_GPIO
 	select DM_KEYBOARD
 	select DM_SERIAL
-	select DM_USB
+	select DM_USB if DISTRO_DEFAULTS
 	select OF_BOARD_SETUP
 	select OF_CONTROL
 	select OF_SEPARATE
 	select SPL_STACK_R if SUPPORT_SPL
 	select SPL_SYS_MALLOC_SIMPLE if SUPPORT_SPL
 	select SYS_NS16550
-	select USB
-	select USB_STORAGE
-	select USB_KEYBOARD
+	select USB if DISTRO_DEFAULTS
+	select USB_STORAGE if DISTRO_DEFAULTS
+	select USB_KEYBOARD if DISTRO_DEFAULTS
 	select USE_TINY_PRINTF
 
 config TARGET_TS4800