Blackfin: bf538: add bfin_clear_PPI_STATUS() helper

Add the bf538 version of bfin_clear_PPI_STATUS() to match all other ports.
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

arch/blackfin/mach-bf538/include/mach/cdefBF538.h

@@ -1310,6 +1310,7 @@
 #define bfin_write_PPI_CONTROL(val)    bfin_write16(PPI_CONTROL, val)
 #define bfin_read_PPI_STATUS()         bfin_read16(PPI_STATUS)
 #define bfin_write_PPI_STATUS(val)     bfin_write16(PPI_STATUS, val)
+#define bfin_clear_PPI_STATUS()        bfin_read_PPI_STATUS()
 #define bfin_read_PPI_DELAY()          bfin_read16(PPI_DELAY)
 #define bfin_write_PPI_DELAY(val)      bfin_write16(PPI_DELAY, val)
 #define bfin_read_PPI_COUNT()          bfin_read16(PPI_COUNT)