serial: pic32_uart: allow driver to be compiled on all architectures with COMPILE_TEST

serial: pic32_uart: allow driver to be compiled on all architectures with COMPILE_TEST

This driver currently only supports builds against a PIC32 target, or
with COMPILE_TEST on MIPS. Now that commit 24cad1a22848 ("serial:
pic32_uart: update include to use pic32.h from platform_data") is
merged, it's possible to compile this driver on other architectures.

To avoid future breakage of this driver in the future, let's update the
Kconfig so that it can be built with COMPILE_TEST enabled on all
architectures.

Signed-off-by: Brian Masney <bmasney@redhat.com>
Link: https://patch.msgid.link/20260222-serial-pic32-v1-1-8fdbc0d0d334@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>