sysdeps: linux: Fix output of LD_SHOW_AUXV=1 for AT_RSEQ_*

sysdeps: linux: Fix output of LD_SHOW_AUXV=1 for AT_RSEQ_*

The constants themselves were added to elf.h back in 8754a4133e but the
array in _dl_show_auxv wasn't modified accordingly, resulting in the
following output when running LD_SHOW_AUXV=1 /bin/true on recent Linux:

    AT_??? (0x1b): 0x1c
    AT_??? (0x1c): 0x20

With this patch:

    AT_RSEQ_FEATURE_SIZE: 28
    AT_RSEQ_ALIGN:        32

Tested on Linux 6.11 x86_64

Signed-off-by: Yannick Le Pennec <yannick.lepennec@live.fr>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>