[RS6000] Replace TLSmode with P, and correct tls call mems

[RS6000] Replace TLSmode with P, and correct tls call mems

There is really no need to define a TLSmode mode iterator that is
identical (since !TARGET_64BIT == TARGET_32BIT) to the much used P
mode iterator.  It's nonsense to think we might ever want to support
32-bit TLS on 64-bit or vice versa!  The patch also fixes a minor
error in the call mems.  All other direct calls use (call (mem:SI ..)).

	* config/rs6000/rs6000.md (TLSmode): Delete mode iterator.  Replace
	with P throughout except for call mems which should use SI.
	(tls_abi_suffix, tls_sysv_suffix, tls_insn_suffix): Delete mode
	attributes.  Replace with bits, mode and ptrload respectively.

From-SVN: r266602