ramips: remove bogus ralink,mtd-eeprom with offset 0x4

Several devices in mt76x8 subtarget use the following line to set
up wmac in their DTS(I) files:

ralink,mtd-eeprom = <&factory 0x4>

This is strange for several reasons:
- They should use mediatek,mtd-eeprom on this SOC
- The caldata is supposed to start at 0x0
- The parent DTSI mt7628an.dtsi specifies mediatek,mtd-eeprom anyway,
  starting from 0x0
- The offset coincides with the default location of the MAC address
  in caldata

Based on the comment in b28e94d4bfa1 ("ramips: MiWiFi Nano fixes"),
it looks like the author for this device wanted to actually use
mtd-mac-address instead of ralink,mtd-eeprom. A check on the same
device revealed that actually the MAC address start at offset 4 there,
so the correct caldata offset is 0x0.

Based on these findings, and the fact that the expected location on
this SOC is 0x0, we remove the "ralink,mtd-eeprom = <&factory 0x4>"
statement from all devices in ramips (being only mt7628an anyway).

Thanks to Sungbo Eo for finding and researching this.

Reported-by: Sungbo Eo <mans0n@gorani.run>
Fixes: b28e94d4bfa1 ("ramips: MiWiFi Nano fixes")
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
(cherry picked from commit 09d38a3bc328d122b0d84fcf6bb53d2bce7373b6)

target/linux/ramips/dts/MIWIFI-NANO.dts

@@ -65,7 +65,6 @@
 
 &wmac {
 	status = "okay";
-	ralink,mtd-eeprom = <&factory 0x4>;
 };
 
 &ethernet {

target/linux/ramips/dts/RAK633.dts

@@ -100,5 +100,4 @@
 
 &wmac {
 	status = "okay";
-	ralink,mtd-eeprom = <&factory 0x4>;
 };

target/linux/ramips/dts/TOTOLINK-LR1200.dts

@@ -108,7 +108,6 @@
 
 &wmac {
 	status = "okay";
-	ralink,mtd-eeprom = <&factory 0x4>;
 };
 
 &ethernet {

target/linux/ramips/dts/VOCORE2.dtsi

@@ -20,7 +20,6 @@
 
 &wmac {
 	status = "okay";
-	ralink,mtd-eeprom = <&factory 0x4>;
 };
 
 &ethernet {

target/linux/ramips/dts/WR1000.dts

@@ -135,7 +135,6 @@
 
 &wmac {
 	status = "okay";
-	ralink,mtd-eeprom = <&factory 0x4>;
 };
 
 &ethernet {

target/linux/ramips/dts/ZBT-WE1226.dts

@@ -111,7 +111,6 @@
 
 &wmac {
 	status = "okay";
-	ralink,mtd-eeprom = <&factory 0x4>;
 };
 
 &ethernet {