powerpc: remove unused chrp_event_scan() declaration

chrp_event_scan() has been removed since
commit 3d541c4b ("powerpc/chrp: Use the same RTAS
daemon as pSeries"), so remove it.
Signed-off-by: NGaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220913075029.682327-4-cuigaosheng1@huawei.com

arch/powerpc/platforms/chrp/chrp.h

@@ -9,4 +9,3 @@ extern int chrp_set_rtc_time(struct rtc_time *);
 extern long chrp_time_init(void);
 
 extern void chrp_find_bridges(void);
-extern void chrp_event_scan(unsigned long);