[llvm] ARM: Remove redundant or buggy config of __aeabi_d2h (PR #152126)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> I think that the other case should be changed. The GNU EABI should use the GNU variant. The AEABI implementation might be compatible with APCS, but definitely is compatible with AAPCS.

I'm not sure exactly what you're saying; I'm not trying to change the used call or behavior, only try to make the exact conditions where the calls are currently used more obvious 

https://github.com/llvm/llvm-project/pull/152126