pinctrl: meson: amlogic-a4: Fix device node reference leak in bank helpers

pinctrl: meson: amlogic-a4: Fix device node reference leak in bank helpers

of_parse_phandle_with_fixed_args() increments the reference count of the
returned device node, so it must be explicitly released using
of_node_put() after use.

Fix the reference leak in aml_bank_pins() and aml_bank_number() by
adding the missing of_node_put() calls.

Fixes: 6e9be3abb78c ("pinctrl: Add driver support for Amlogic SoCs")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Reviewed-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>