vdso: Drop kconfig GENERIC_COMPAT_VDSO

This configuration is never used.

Remove it.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/all/20250826-vdso-cleanups-v1-8-d9b65750e49f@linutronix.de

Author: t-8ch

arch/arm64/Kconfig

@@ -1782,7 +1782,6 @@ config COMPAT_VDSO
 	bool "Enable vDSO for 32-bit applications"
 	depends on !CPU_BIG_ENDIAN
 	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
-	select GENERIC_COMPAT_VDSO
 	default y
 	help
 	  Place in the process address space of 32-bit applications an

lib/vdso/Kconfig

@@ -12,11 +12,6 @@ config GENERIC_GETTIMEOFDAY
 	  Each architecture that enables this feature has to
 	  provide the fallback implementation.
 
-config GENERIC_COMPAT_VDSO
-	bool
-	help
-	  This config option enables the compat VDSO layer.
-
 config GENERIC_VDSO_TIME_NS
 	bool
 	help