hpet: remove hpets::hp_clocksource

Commit cf8e8658 (arch: Remove Itanium (IA-64) architecture) removed
the last user of hpets::hp_clocksource. Drop the member.

Found by https://github.com/jirislaby/clang-struct.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240213111527.25218-1-jirislaby@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/char/hpet.c

@@ -87,7 +87,6 @@ struct hpets {
 	struct hpets *hp_next;
 	struct hpet __iomem *hp_hpet;
 	unsigned long hp_hpet_phys;
-	struct clocksource *hp_clocksource;
 	unsigned long long hp_tick_freq;
 	unsigned long hp_delta;
 	unsigned int hp_ntimer;