gpio: loongson: Add 3A/3B/3C/7A gpio dirver support

LoongArch inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I6BWFP



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Change-Id: Ib1adc61f5279bba8020f26acc32a4de4dee95df5
Signed-off-by: Juxin Gao <gaojuxin@loongson.cn>
(cherry picked from commit 3c16558b)