UPSTREAM: arm64: vdso32: make vdso32 install conditional

vdso32 should only be installed if CONFIG_COMPAT_VDSO is enabled,
since it's not even supposed to be compiled otherwise, and arm64
builds without a 32bit crosscompiler will fail.

Bug: 254441685
Fixes: 8d75785a8142 ("ARM64: vdso32: Install vdso32 from vdso_install")
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Cc: stable@vger.kernel.org [5.4+]
Link: https://lore.kernel.org/r/20200827234012.19757-1-fllinden@amazon.com


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 5d28ba5f8a0cfa3a874fa96c33731b8fcd141b3a)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: Id2cc0850326d78f437130dcb4fd6f75a6bb336ed