[AArch64][RegisterBankInfo] Use the generic implementation of copyCost.

Long term we may want to give high cost at FPR to/from GPR copies.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272086 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed