[gdb/testsuite] Fix gdbsever typo

I noticed a typo in the testsuite, twice: gdbsever.  Fix these.

Codespell doesn't detect it, so add a new file
gdb/contrib/codespell-dictionary.txt that contains a gdbsever->gdbserver
entry, and update gdb/contrib/setup.cfg to use it.

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

gdb/contrib/codespell-dictionary.txt

@@ -0,0 +1 @@
+gdbsever->gdbserver

gdb/contrib/setup.cfg

@@ -4,6 +4,7 @@
 skip = */ChangeLog*,*/configure,gdbsupport/Makefile.in,*.dat,*.eps,gdb/features/*.c,gdb/ada-casefold.h,gdb/copying.c,gdb/gdbarch-gen.h,gdb/gdbarch-gen.c,gdb/target-delegates-gen.c
 
 ignore-words = gdb/contrib/codespell-ignore-words.txt
+dictionary = gdb/contrib/codespell-dictionary.txt,-
 
 # Ignore all URLs.
 uri-ignore-words-list = *

gdb/testsuite/gdb.replay/connect.exp

@@ -13,7 +13,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 #
-# Starts a communication with gdbsever setting the remotelog file.
+# Starts a communication with gdbserver setting the remotelog file.
 # Modifies the remotelog with update_log proc, injects an error message
 # instead of the expected replay to the vMustReplyEmpty packet in order
 # to test GDB reacts to the error response properly. After the remotelog

gdb/testsuite/gdb.trace/tspeed.exp

@@ -17,7 +17,7 @@ load_lib "trace-support.exp"
 
 require allow_shlib_tests
 
-# Do not run if gdbsever debug is enabled - the output file is many Gb.
+# Do not run if gdbserver debug is enabled - the output file is many Gb.
 if [gdbserver_debug_enabled] {
     return 0
 }