soc: bcm: brcmstb: biuctrl: Avoid double of_node_put()

Commit 9a073d4f ("soc: bcm: brcmstb: biuctrl: Add missing
of_node_put()") added what was thought to be a missing of_node_put() but
now causes a double of_node_put() to be called, once from
setup_hifcpubiuctrl_regs() and another time from brcmstb_biuctrl_init().

Ensure that setup_hifcpubiuctrl_regs() is not calling of_node_put()
since it is not obvious it does that on one of its parameters.

Fixes: 9a073d4f

 ("soc: bcm: brcmstb: biuctrl: Add missing of_node_put()")
Reported-by: Jim Quinlan <jim2101024@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Change-Id: I1c405c36c2f06c8b8c0f684143b7a52db7e809f0