x86/vdso/vdso2c: Remove page handling

The values are not used anymore.
Also the sanity checks performed by vdso2c can never trigger as they
only validate invariants already enforced by the linker script.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-16-13a4669dfc8c@linutronix.de