gdbserver: adjust init_target_desc call in tic6x_read_description

gdbserver: adjust init_target_desc call in tic6x_read_description

I spotted this call missing an argument.

For context, init_target_desc gained this osabi parameter in this
commit:

    Author:     Andrew Burgess <aburgess@redhat.com>
    AuthorDate: Fri Oct 4 19:30:04 2024 +0100
    Commit:     Andrew Burgess <aburgess@redhat.com>
    CommitDate: Tue Nov 12 12:51:36 2024 +0000

        gdbserver: pass osabi to GDB in more target descriptions

This bug was present in GDB 16.  I wonder if anybody uses this today.

Change-Id: Id5483be3efa0ca9d238d59af8abae94e8bdbd57c
Approved-By: Tom Tromey <tom@tromey.com>