[AArch64] Adjust the cost model for Exynos M1 and M2

Refine the model of loads and stores using the register offset addressing
modes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313554 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed