vdso: Drop Kconfig GENERIC_VDSO_TIME_NS

All architectures implementing time-related functionality in the vDSO are
using the generic vDSO library which handles time namespaces properly.

Remove the now unnecessary Kconfig symbol.

Enables the use of time namespaces on architectures, which use the
generic vDSO but did not enable GENERIC_VDSO_TIME_NS, namely MIPS and arm.

Signed-off-by: Thomas Weißschuh <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>
Acked-by: Catalin Marinas <[e-mail]>
Link: https://lore.kernel.org/all/[e-mail]

arch/arm64/Kconfig

···
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
-	select GENERIC_VDSO_TIME_NS
 	select HARDIRQS_SW_RESEND
 	select HAS_IOPORT
 	select HAVE_MOVE_PMD

arch/loongarch/Kconfig

···
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
-	select GENERIC_VDSO_TIME_NS
 	select GPIOLIB
 	select HAS_IOPORT
 	select HAVE_ARCH_AUDITSYSCALL

arch/powerpc/Kconfig

···
 	select GENERIC_PCI_IOMAP		if PCI
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
-	select GENERIC_VDSO_TIME_NS
 	select HAS_IOPORT			if PCI
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_HUGE_VMALLOC		if HAVE_ARCH_HUGE_VMAP

arch/riscv/Kconfig

···
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL if GENERIC_GETTIMEOFDAY
-	select GENERIC_VDSO_TIME_NS if GENERIC_GETTIMEOFDAY
 	select HARDIRQS_SW_RESEND
 	select HAS_IOPORT if MMU
 	select HAVE_ALIGNED_STRUCT_PAGE

arch/s390/Kconfig

···
 	select GENERIC_GETTIMEOFDAY
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
-	select GENERIC_VDSO_TIME_NS
 	select GENERIC_IOREMAP if PCI
 	select HAVE_ALIGNED_STRUCT_PAGE
 	select HAVE_ARCH_AUDITSYSCALL

arch/x86/Kconfig

···
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
-	select GENERIC_VDSO_TIME_NS
 	select GENERIC_VDSO_OVERFLOW_PROTECT
 	select GUP_GET_PXX_LOW_HIGH		if X86_PAE
 	select HARDIRQS_SW_RESEND

init/Kconfig

···
 
 config TIME_NS
 	bool "TIME namespace"
-	depends on GENERIC_VDSO_TIME_NS
+	depends on GENERIC_GETTIMEOFDAY
 	default y
 	help
 	  In this namespace boottime and monotonic clocks can be set.

lib/vdso/Kconfig

···
 	  Each architecture that enables this feature has to
 	  provide the fallback implementation.
 
-config GENERIC_VDSO_TIME_NS
-	bool
-	help
-	  Selected by architectures which support time namespaces in the
-	  VDSO
-
 config GENERIC_VDSO_OVERFLOW_PROTECT
 	bool
 	help

tools/testing/selftests/pidfd/config

···
 CONFIG_PID_NS=y
 CONFIG_NET_NS=y
 CONFIG_TIME_NS=y
-CONFIG_GENERIC_VDSO_TIME_NS=y
 CONFIG_CGROUPS=y
 CONFIG_CHECKPOINT_RESTORE=y