watchdog: hpwdt (4/12): Despecificate driver from iLO2

This driver supports both iLO2 and iLO3, but our user-visible strings
currently only reference iLO2. Let's just call it "iLO2+" to avoid having
to update strings for each iLO generation. This driver doesn't support
iLO ASICs prior to iLO2, but that is sufficiently explained in Kconfig.

Signed-off-by: dann frazier <dannf@hp.com>
Acked-by: Thomas Mingarelli <Thomas.Mingarelli@hp.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>