include: Add target_cont_splash_screen function declaration to target.h

Add target_cont_splash_screen declaration to target.h

Change-Id: Ic3efc93cf895d1890bd4644b9c750bac79b70b10
diff --git a/include/target.h b/include/target.h
index 055fdb7..4a2891c 100644
--- a/include/target.h
+++ b/include/target.h
@@ -84,4 +84,5 @@
 int _emmc_recovery_init(void);
 void ulpi_write(unsigned val, unsigned reg);
 void target_crypto_init_params(void);
+int target_cont_splash_screen(void);
 #endif