PR30697, ppc32 mix of local-dynamic and global-dynamic TLS

This fixes miscounting of dynamic relocations on GOT entries when
a) there are both local-dynamic and global-dynamic tls accesss for a
   given symbol, and
b) the symbol is global with non-default visibility, and
c) the __tls_get_addr calls aren't optimised away.

	PR 30697
bfd/
	* elf32-ppc.c (allocate_dynrelocs): Correct local-dynamic
	reloc count.
ld/
	* testsuite/ld-powerpc/tls32ldgd.d,
	* testsuite/ld-powerpc/tls32ldgd.s: New test.
	* testsuite/ld-powerpc/powerpc.exp: Run it.

(cherry picked from commit ae337712)