imx: ventana: move GSC boot watchdog disable function to gsc.c

Move the code that disables the GSC boot watchdog into gsc.c

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
diff --git a/board/gateworks/gw_ventana/gsc.h b/board/gateworks/gw_ventana/gsc.h
index 2d4969e..e0c0ed0 100644
--- a/board/gateworks/gw_ventana/gsc.h
+++ b/board/gateworks/gw_ventana/gsc.h
@@ -66,5 +66,6 @@
 int gsc_i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len);
 int gsc_i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len);
 int gsc_info(int verbose);
+int gsc_boot_wd_disable(void);
 #endif