Update alpha localplt.data.

This patch updates alpha localplt.data so the localplt test passes in
my compile-only all-ABIs glibc testing.  The failures I see without
this patch are:

Missing required PLT reference: ld.so: __tls_get_addr
Missing required PLT reference: ld.so: free

Now, __tls_get_addr can be made optional.  For free, rather than
making it optional as in libc.so it seems better to mark all the
malloc-related symbols in both libc.so and ld.so as allowing an
R_ALPHA_GLOB_DAT relocation as an alternative to using a PLT entry, so
this patch does so.

Tested for alpha.

	* sysdeps/unix/sysv/linux/alpha/localplt.data: Make __tls_get_addr
	optional in ld.so.  Allow R_ALPHA_GLOB_DAT relocation for malloc,
	calloc, realloc, free, memalign and __libc_memalign rather than
	making them optional.