net: replace the "xfi" phy-mode with "10gbase-r"

As part of the effort of making U-Boot work with the same device tree as
Linux, there is an issue with the "xfi" phy-mode. To be precise, in
Linux there was a discussion (for those who have time to read:
https://lore.kernel.org/netdev/1576768881-24971-2-git-send-email-madalin.bucur@oss.nxp.com/)

which led to a patch:
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=c114574ebfdf42f826776f717c8056a00fa94881

TL;DR: "xfi" was standardized in Linux as "10gbase-r".

This patch changes the relevant occurrences in U-Boot to use "10gbase-r"
instead of "xfi" wherever applicable.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
diff --git a/drivers/net/fm/b4860.c b/drivers/net/fm/b4860.c
index 5be0ad2..6e3d008 100644
--- a/drivers/net/fm/b4860.c
+++ b/drivers/net/fm/b4860.c
@@ -100,7 +100,7 @@
 			env_get_f("hwconfig", buffer, sizeof(buffer));
 			buf = buffer;
 
-			/* check if XFI interface enable in hwconfig for 10g */
+			/* check if 10GBase-R interface enable in hwconfig for 10g */
 			if (hwconfig_subarg_cmp_f("fsl_b4860_serdes2",
 						  "sfp_amc", "sfp", buf)) {
 				if ((port == FM1_10GEC1 ||