[FS#992] bad system clock on MT7620A

[LEDE Bugs]

The following task has a new comment added:

FS#992 - bad system clock on MT7620A
User who did this - psyborg55 (psyborg55)

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you are done in hardware...

i've overridden this in software and noticed improvement
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More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=992#comment3368