powerpc/ppc-opcode: Fold PPC_INST_* macros into PPC_RAW_* macros

Lots of PPC_INST_* macros are used only ever in PPC_* macros, fold
those PPC_INST_* into PPC_RAW_* to avoid using PPC_INST_*
accidentally.

Signed-off-by: Balamuruhan S <bala24@linux.ibm.com>
Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
[mpe: Deal with PHWSYNC, PLWSYNC]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200624113038.908074-7-bala24@linux.ibm.com