[gdb/testsuite] Add read1 and readmore to make-check-all.sh

There are two useful ways to run a test-case, that are not represented by a
board file in gdb/testsuite/boards: check-read1 and check-readmore.

Consequently, they're not run either by make-check-all.sh.

Fix this by adding check-read1 and check-readmore to make-check-all.sh.

Tested on x86_64-linux.  Verified with shellcheck.

Approved-By: Andrew Burgess <aburgess@redhat.com>
1 file changed