MIPS: VDSO: Fold MIPS_CLOCK_VSYSCALL into MIPS_GENERIC_GETTIMEOFDAY

MIPS: VDSO: Fold MIPS_CLOCK_VSYSCALL into MIPS_GENERIC_GETTIMEOFDAY

This configuration option exists so "that we don't provide the symbol
when there's no possibility of there being a usable clocksource".
However it only covers __vdso_gettimeofday() and none of the other vDSO
functions which should be affected by the same circumstances.slightly slightly.

Remove MIPS_CLOCK_VSYSCALL and fold its usecase into
MIPS_GENERIC_GETTIMEOFDAY, which works correctly.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Daniel Lezcano <daniel.lezcano@kernel.org>
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-mips@vger.kernel.org
Link: https://patch.msgid.link/20260521-vdso-mips-kconfig-v1-9-2f79dcd6c78f@linutronix.de