[NFC][PowerPC] Reorganize CRNotPat multiclass patterns in PPCInstrInfo.td

This is patch aims to group together the `CRNotPat` multi class instantiations
within the `PPCInstrInfo.td` file.

Integer instantiations of the multi class are grouped together into a section,
and the floating point patterns are separated into its own section.

Differential Revision: https://reviews.llvm.org/D67975

llvm-svn: 373869