Input: i8042 - Add PNP checking hook for Loongson

LoongArch inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5OHOB



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Add PNP checking related functions for Loongson, so that i8042 driver
can work well under the ACPI firmware with PNP typed keyboard and mouse
configured in DSDT.

Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>