Wrong MAC address byte ordering

[GeoffreyBultot]

MAC addres byte ordering is wrong in the EEPROM_MAC module under device/eeprom.py.
Here is my observations: https://github.com/railnova/Litex-DataDiode/pull/13
And here is my fix: railnova@cd58d7c
The testbench could be updated according.

To simplify understanding, here is a diff with my changes:

diff --git a/regmap/devices/eeprom.py b/regmap/devices/eeprom.py
index 1e9ef89..b83a46a 100644
--- a/regmap/devices/eeprom.py
+++ b/regmap/devices/eeprom.py
@@ -105,7 +105,7 @@ class EEPROM_MAC(EEPROM_24):
                 NextValue(bytes_read, bytes_read + 1),
                 If(bytes_read != 0,
                     Case(bytes_read, {
-                        i + 1: [NextValue(eui.eui[i * 8 : i * 8 + 8], i2c_sink.data)]
+                        i + 1: [NextValue(eui.eui[(5-i) * 8 : (5-i) * 8 + 8], i2c_sink.data)]
                         for i in range(6)}),
                     NextState("READ_SETUP"),
                 ),