clk: imx6ul: fix missing of_node_put()

[ Upstream commit 11177e7a7aaef95935592072985526ebf0a3df43 ]

of_find_compatible_node() is returning a device node with refcount
incremented and must be explicitly decremented after the last use
which is right after the us in of_iomap() here.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Fixes: 787b4271 ("clk: imx: add imx6ul clk tree support")
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>