can: sja1000: limit PEAK PCAN-PC Card to HAS_IOPORT

This patch limits the PEAK PCAN-PC Card driver to systems with ioports. Fixes a
compile time breakage on SH:

    drivers/net/can/sja1000/peak_pcmcia.c:626:2: error:
        implicit declaration of function 'ioport_unmap'

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/sja1000/Kconfig

@@ -46,6 +46,7 @@ config CAN_EMS_PCI
 config CAN_PEAK_PCMCIA
 	tristate "PEAK PCAN-PC Card"
 	depends on PCMCIA
+	depends on HAS_IOPORT
 	---help---
 	  This driver is for the PCAN-PC Card PCMCIA adapter (1 or 2 channels)
 	  from PEAK-System (http://www.peak-system.com). To compile this