clk: mvebu: armada-37xx-periph: Fix the clock provider registration

clk: mvebu: armada-37xx-periph: Fix the clock provider registration

While trying using a peripheral clock on a driver, I saw that the clock
pointer returned by the provider was NULL.

The problem was a missing indirection. It was the pointer stored in the
hws array which needed to be updated not the value it contains.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Fixes: 86cb8f31f6d7 ("clk: mvebu: Add the peripheral clock driver for Armada 3700")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>