ASoC: loongson: Refactor DMA and regmap handling

Binbin Zhou <zhoubinbin@loongson.cn> says:

This series refactors the Loongson I2S ASoC drivers, reducing code
duplication and improving DMA differentiation. It also adds an entry
in MAINTAINERS and applies a few fixes to the es8323 codec driver.

These changes have been tested on Loongson-2K0300 (platform, eDMA) and
Loongson-2K2000 (PCI, iDMA) boards.

Link: https://patch.msgid.link/cover.1780304703.git.zhoubinbin@loongson.cn

diff --cc MAINTAINERS
Simple merge