x86/vgtod: Remove unused typedef gtod_long_t

The typedef gtod_long_t is not used anymore so remove it.

The header file contains then only includes dependent on
CONFIG_GENERIC_GETTIMEOFDAY to not break ARCH=um. Nevertheless, keep the
header file only with those includes to prevent spreading ifdeffery all
over the place.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lore.kernel.org/r/20240701-vdso-cleanup-v1-4-36eb64e7ece2@linutronix.de

arch/x86/include/asm/vgtod.h

@@ -14,11 +14,6 @@
 
 #include <uapi/linux/time.h>
 
-#ifdef BUILD_VDSO32_64
-typedef u64 gtod_long_t;
-#else
-typedef unsigned long gtod_long_t;
-#endif
 #endif /* CONFIG_GENERIC_GETTIMEOFDAY */
 
 #endif /* _ASM_X86_VGTOD_H */