[coreboot-gerrit] Change in coreboot[master]: helpers: Add fls support

[Jianjun Wang (Code Review)]

Attention is currently required from: Hung-Te Lin, Shelley Chen, Paul Menzel, Julius Werner, Yu-Ping Wu.
Jianjun Wang has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/59738 )

Change subject: helpers: Add fls support
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Patch Set 1:

(1 comment)

Patchset:

PS1:
> > I will abandon this patch and use __ffs instead. […]

Of course not, but I found there are some misunderstandings, __ffs only calculate the first significant bit, e.g. fls(0x3000000) = 26, __ffs(0x3000000) = 24, clz(0x3000000) = 6.

So just like Julius said, we should either use clz(), or add another function to implements fls() by calling clz(), what do you think?