[AArch64][SVE2] Implement remaining SVE2 floating-point intrinsics

Summary:
Adds the following intrinsics:
  - faddp
  - fmaxp, fminp, fmaxnmp & fminnmp
  - fmlalb, fmlalt, fmlslb & fmlslt
  - flogb

Reviewers: huntergr, sdesmalen, dancgr, efriedma

Reviewed By: sdesmalen

Subscribers: efriedma, tschuett, kristof.beyls, hiraditya, cameron.mcinally, cfe-commits, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70253