[][kernel][mt7986][spi][spi-calibration: Add support for 4B mode NOR flashes]

Add support for 4B mode NOR flashes:
* For NOR flash, we'll calibrate with 3 bytes mode first and then 4 bytes mode.
* Remove controller's calibration data each time after calibration. We'll
append them again if another calibration is needed.
* Correct error code.


Change-Id: Ia647cfa9b1e6228555b568184a5944a592ebe0c1
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7104709
3 files changed