pps: Fix build breakage from decoupling pps from tty

Fixes:
tree:   git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-next
head:   bc80fbe4
commit: 593fb1ae pps: Move timestamp read into PPS code proper
date:   78 minutes ago
config: make ARCH=sparc defconfig

All error/warnings:

   In file included from drivers/tty/serial/suncore.c:20:0:
>> include/linux/sunserialcore.h:29:15: warning: 'struct device_node' declared inside parameter list [enabled by default]
>> include/linux/sunserialcore.h:29:15: warning: its scope is only this definition or declaration, which is probably not what you want [enabled by default]
>> include/linux/sunserialcore.h:31:18: warning: 'struct device_node' declared inside parameter list [enabled by default]
>> drivers/tty/serial/suncore.c:55:5: error: conflicting types for 'sunserial_console_match'
   include/linux/sunserialcore.h:28:12: note: previous declaration of 'sunserial_console_match' was here
>...