ARC: [plat-hsdk]: fix USB regression

As of today the CONFIG_USB isn't explicitly present in HSDK defconfig
as it is implicitly forcibly enabled by UDL driver which selects CONFIG_USB
in its kconfig.
The commit 5d50bd44 ("drm/udl: Make udl driver depend on CONFIG_USB")
reverse the dependencies between UDL and USB so UDL now depends on
CONFIG_USB and not selects it. This introduces regression for ARC HSDK
board as HSDK defconfig wasn't adjusted and now it misses USB support
due to lack of CONFIG_USB enabled.

Fix that.

Cc: <stable@vger.kernel.org> # 5.6.x
Fixes: 5d50bd44 ("drm/udl: Make udl driver depend on CONFIG_USB")
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>