debug/elf: fix typo in R_PPC64_TPREL34 and R_PPC64_DTPREL34

debug/elf: fix typo in R_PPC64_TPREL34 and R_PPC64_DTPREL34

The suffix should be 34 not 28. I misread the name because the
reloc listed before these two in the ABI is named "R_PC64_PCREL28".

Updates #54345

Change-Id: Ie8238f55e441c787d70ead58e0a177c650f8b89e
Reviewed-on: https://go-review.googlesource.com/c/go/+/435415
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Run-TryBot: Paul Murphy <murp@ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>