MIPS: Loongson64: Add Loongson-2K1000 early_printk_port

Distinguish between Loongson-3A series CPU and Loongson-2K1000 CPU UART0.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
Tested-by: Ming Wang <wangming01@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/loongson64/init.c

@@ -120,7 +120,10 @@ void __init prom_init(void)
 #endif
 
 	/* Hardcode to CPU UART 0 */
-	setup_8250_early_printk_port(TO_UNCAC(LOONGSON_REG_BASE + 0x1e0), 0, 1024);
+	if ((read_c0_prid() & PRID_IMP_MASK) == PRID_IMP_LOONGSON_64R)
+		setup_8250_early_printk_port(TO_UNCAC(LOONGSON_REG_BASE), 0, 1024);
+	else
+		setup_8250_early_printk_port(TO_UNCAC(LOONGSON_REG_BASE + 0x1e0), 0, 1024);
 
 	register_smp_ops(&loongson3_smp_ops);
 	board_nmi_handler_setup = mips_nmi_setup;