Fix readahead section value parsing or even better remove this error prone redundant part

[watologo1]

readahead=4092
readahead=>4092
works just fine as expected.
Things get unnecessary complicated, error prone and buggy when one tries to specify the value in sectors instead of kib:

readahead=4092 s
readahead = 4092 s
-> The sector value is simply divided by 2 and passed the same way as the kib value.
IMO this redundancy is not needed and should not be allowed.
In this case dividing by 2 results in a float type which gets parsed to a string when applied to sysfs and one might get:
2024-11-06 09:52:03,273 ERROR tuned.plugins.base: verify: failed: device md127: 'readahead' = '2048', expected '2048.0'

readahead=>4092 s
Here things seem to break even worse:
2024-11-19 07:51:42,945 WARNING tuned.plugins.base: cannot compare new value '8192 s' with current value '512' by operator '>', using '>8192 s' directly as new value
For the "=>" operator it seems to be a bad idea to pass such non integer or double meaning types.

This part is a bit more abstract and it nicely shows that such (redundant/unnecessary) complexity is a bad idea. People should just use kib?

I can come up with a patch if this is considered the correct approach.