binutils: remove unneeded CFLAGS

[danielnachun]

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[danielnachun]

Now that Homebrew/brew#13588 and Homebrew/brew#13568 are merged, we can drop the CFLAGS we were adding to fix the build.

[carlocab]

Do we need new bottles for this?

[iMichka]

I think we don't need new bottles; all of these changes are build time only.

[BrewTestBot]

🤖 A scheduled task has triggered a merge.