PPC64: fix wrong ifdef for SYSV ABI

The TOC is used by PPC64, not by PPC32. Resolves #39571

(cherry picked from commit 14289173bbaf1c7bb4c91808f065122198c9f047)

compiler/systems.pas

@@ -395,7 +395,7 @@ interface
 
        { all PPC ABIs that use a TOC register to address globals }
        abis_ppc_toc = [
-         {$ifdef powerpc32}abi_powerpc_sysv,{$endif}abi_powerpc_aix,abi_powerpc_elfv2
+         {$ifdef powerpc64}abi_powerpc_sysv,{$endif}abi_powerpc_aix,abi_powerpc_elfv2
        ];
 
        { pointer checking (requires special code in FPC_CHECKPOINTER,