wl1251: convert 32-bit values to le32 before writing to the chip

The 32-bit values were not converted before writing them to the chip.
Change the wl1251_read32() and wl1251_write32() so that they always
read and write le32 values and convert to and from the CPU endianess.

Signed-off-by: Luciano Coelho <coelho@ti.com>
diff --git a/drivers/net/wireless/wl1251/wl1251.h b/drivers/net/wireless/wl1251/wl1251.h
index a77f1bb..9d8f581 100644
--- a/drivers/net/wireless/wl1251/wl1251.h
+++ b/drivers/net/wireless/wl1251/wl1251.h
@@ -380,7 +380,7 @@
 	struct wl1251_stats stats;
 	struct wl1251_debugfs debugfs;
 
-	u32 buffer_32;
+	__le32 buffer_32;
 	u32 buffer_cmd;
 	u8 buffer_busyword[WL1251_BUSY_WORD_LEN];
 	struct wl1251_rx_descriptor *rx_descriptor;