Convert ISO-8859 files to UTF-8

There was a mix of UTF-8 and ISO-8859 files in the U-Boot source
tree, which could cause issues with the patchwork review system.
This commit converts all ISO-8859 files to UTF-8.

Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
diff --git a/board/lwmon/lwmon.c b/board/lwmon/lwmon.c
index 9d6c21f..b5e524b 100644
--- a/board/lwmon/lwmon.c
+++ b/board/lwmon/lwmon.c
@@ -365,7 +365,7 @@
 	 *
 	 * This is just a preliminary fix, intended to turn off TENA
 	 * as soon as possible to avoid noise on the network. Once
-	 * I²C is running we will make sure the interface is
+	 * I2C is running we will make sure the interface is
 	 * correctly initialized.
 	 */
 	immr->im_cpm.cp_pbpar &= ~PB_ENET_TENA;