[docs] Update supported chip list, remove AmebaZ2 boards for now

Author: kuba2k2

boards/bw15.json

@@ -38,11 +38,15 @@ typedef enum {
 	RTL8710L0 = CPU_MODEL(F_RTL8710B, 0xFB), // CHIPID_8710BN_L0 / QFN32
 	RTL8711BN = CPU_MODEL(F_RTL8710B, 0xFD), // CHIPID_8711BN / QFN48
 	RTL8711BU = CPU_MODEL(F_RTL8710B, 0xFC), // CHIPID_8711BG / QFN68
+	MX1290	  = RTL8710BN,
+	MX1290V2  = RTL8710BX,
 	// Beken 72XX
 	BK7231T = CPU_MODEL(F_BK7231U, 0x1A), // *SCTRL_CHIP_ID = 0x7231a
 	BK7231N = CPU_MODEL(F_BK7231N, 0x1C), // *SCTRL_CHIP_ID = 0x7231c
-	BL2028N = CPU_MODEL(F_BK7231N, 0x1C), // *SCTRL_CHIP_ID = 0x7231c
 	BK7252	= CPU_MODEL(F_BK7251, 0x00),  // TODO
+	BL2028N = BK7231N,
+	BK7231S = BK7231T,
+	BK7231U = BK7231T,
 } lt_cpu_model_t;
 
 /**