clk: versatile: clk-icst: Ensure clock names are unique

Commit 2d3de197 ("ARM: dts: arm: Update ICST clock nodes 'reg' and
node names") moved to using generic node names. That results in trying
to register multiple clocks with the same name. Fix this by including
the unit-address in the clock name.

Fixes: 2d3de197 ("ARM: dts: arm: Update ICST clock nodes 'reg' and node names")
Cc: stable@vger.kernel.org
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-clk@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20211109164650.2233507-3-robh@kernel.org