irqchip/loongson-eiointc: Fix incorrect use of acpi_get_vec_parent

In eiointc_acpi_init(), a *eiointc* node is passed into
acpi_get_vec_parent() instead of a required *NUMA* node (on some chip
like 3C5000L, a *NUMA* node means a *eiointc* node, but on some chip
like 3C5000, a *NUMA* node contains 4 *eiointc* nodes), and node in
struct acpi_vector_group is essentially a *NUMA* node, which will
lead to no parent matched for passed *eiointc* node. so the patch
adjusts code to use *NUMA* node for parameter node of
acpi_set_vec_parent/acpi_get_vec_parent.

Cc: stable@vger.kernel.org
Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230407083453.6305-3-lvjianmin@loongson.cn