clk: imx: imx8mp: add shared clk gate for usb suspend clk

[ Upstream commit ed1f4ccf ]

32K usb suspend clock gate is shared with usb_root_clk, this
shared clock gate was initially defined only for usb suspend
clock, usb suspend clk is kept on while system is active or
system sleep with usb wakeup enabled, so usb root clock is
fine with this situation; with the commit cf7f3f4f
("clk: imx8mp: fix usb_root_clk parent"), this clock gate is
changed to be for usb root clock, but usb root clock will
be off while usb is suspended, so usb suspend clock will be
gated too, this cause some usb functionalities will not work,
so define this clock to be a shared clock gate to conform with
the real HW status.

Fixes: 9c140d99

 ("clk: imx: Add support for i.MX8MP clock driver")
Cc: stable@vger.kernel.org # v5.19+
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/1664549663-20364-2-git-send-email-jun.li@nxp.com
Signed-off-by: Sasha Levin <sashal@kernel.org>