UPSTREAM: lib: vdso: Remove CROSS_COMPILE_COMPAT_VDSO

arm64 was the last architecture using CROSS_COMPILE_COMPAT_VDSO config
option. With this patch series the dependency in the architecture has
been removed.

Remove CROSS_COMPILE_COMPAT_VDSO from the Unified vDSO library code.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
(cherry picked from commit 50a2610adec9d796b25e262734edb56ef324ce15)
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Bug: 154668398
Change-Id: I5cd788546e59e71b76af68cf845e8dd45a6bdc61