ARM: OMAP2+: omap4-common: Fix refcount leak bug

In omap4_sram_init(), of_find_compatible_node() will return a node
pointer with refcount incremented. We should use of_node_put() when
it is not used anymore.

Signed-off-by: Liang He <windhl@126.com>
Message-Id: <20220628112939.160737-1-windhl@126.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>