serial: pic32_uart: update include to use pic32.h from platform_data

serial: pic32_uart: update include to use pic32.h from platform_data

Use the linux/platform_data/pic32.h include instead of
asm/mach-pic32/pic32.h so that the asm variant can be dropped. This
is in preparation for allowing some drivers to be compiled on other
architectures with COMPILE_TEST enabled.

Signed-off-by: Brian Masney <bmasney@redhat.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>