misc: (at24) move header to linux/platform_data/

This patch moves the at24.h header from include/linux/i2c to
include/linux/platform_data and updates existing support accordingly.

It also fixes the following checkpatch warning:

    WARNING: please, no space before tabs
    #436: FILE: include/linux/platform_data/at24.h:31:
    + * ^Iu8 *mac_addr = ethernet_pdata->mac_addr;$

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
diff --git a/arch/arm/mach-pxa/stargate2.c b/arch/arm/mach-pxa/stargate2.c
index 62aea3e..01de542 100644
--- a/arch/arm/mach-pxa/stargate2.c
+++ b/arch/arm/mach-pxa/stargate2.c
@@ -27,7 +27,7 @@
 
 #include <linux/i2c/pxa-i2c.h>
 #include <linux/i2c/pcf857x.h>
-#include <linux/i2c/at24.h>
+#include <linux/platform_data/at24.h>
 #include <linux/smc91x.h>
 #include <linux/gpio.h>
 #include <linux/leds.h>