p54: improve eeprom parser

Like other vendors, p54* devices have a checksum for
the EEPROM descriptor data. This patch enhances the
parser code to generate and verify the data fields,
before initializing the radio-chip on the card.

Note:
	If you have to bootstrap an alternative EEPROM image
	for your device and you don't know how to generate a
	valid crc ccitt checksum, you should take a look at:
	http://git.kernel.org/?p=linux/kernel/git/chr/p54tools.git

	The "checksum" utility loads a binary p54 EEPROM blob
	(use the -f switch, to skip the check) and applies
	the correct crc automatically.

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/p54/Kconfig b/drivers/net/wireless/p54/Kconfig
index b0342a5..60a930e 100644
--- a/drivers/net/wireless/p54/Kconfig
+++ b/drivers/net/wireless/p54/Kconfig
@@ -2,6 +2,7 @@
 	tristate "Softmac Prism54 support"
 	depends on MAC80211 && EXPERIMENTAL
 	select FW_LOADER
+	select CRC_CCITT
 	---help---
 	  This is common code for isl38xx/stlc45xx based modules.
 	  This module does nothing by itself - the USB/PCI/SPI front-ends