configure.ac: Tag version 2.2
configure.ac: Tag version 2.2

Changes since v2.1:
 - Add a missing include to fix a build issue on ppc32
 - Bugfix for the '-l' option when using htm

Signed-off-by: Alistair Popple <e9adbcf81c8a36ccc628e09bc92d0e25e1c8e501@popple.id.au>

open-power/pdbg,open-power/pdbg,open-power/pdbg