WAN: Port COSA driver to generic HDLC.

Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>
diff --git a/drivers/net/wan/Kconfig b/drivers/net/wan/Kconfig
index 846be60..e08cd4b 100644
--- a/drivers/net/wan/Kconfig
+++ b/drivers/net/wan/Kconfig
@@ -37,7 +37,7 @@
 # The COSA/SRP driver has not been tested as non-modular yet.
 config COSA
 	tristate "COSA/SRP sync serial boards support"
-	depends on ISA && m && ISA_DMA_API
+	depends on ISA && m && ISA_DMA_API && HDLC
 	---help---
 	  Driver for COSA and SRP synchronous serial boards.