PCI: xilinx: Drop obsolete dependency on COMPILE_TEST

Since commit 0166dc11 ("of: make CONFIG_OF user selectable"), it is
possible to test-build any driver which depends on OF on any architecture
by explicitly selecting OF. Therefore depending on COMPILE_TEST as an
alternative is no longer needed.

Link: https://lore.kernel.org/r/20230407190843.529caf19@endymion.delvare


Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: "Krzysztof Wilczyński" <kw@linux.com>