clk: keystone: Enable TISCI clocks if K3_ARCH

[ Upstream commit 2f149e6e ]

K3_ARCH uses TISCI for clocks as well. Enable the same
for the driver support.

Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>