mips: don't hardcode Malta env baudrate

The baudrate passed to Linux in the environment was hardcoded at 38400.
Instead pass the correct baudrate from global data, allowing Linux to
correctly inherit the baudrate used by U-boot when console setup is not
explicitly specified.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>

arch/mips/lib/bootm.c

@@ -196,8 +196,10 @@ static void boot_prep_linux(bootm_headers_t *images)
 	if (cp)
 		linux_env_set("eth1addr", cp);
 
-	if (mips_boot_malta)
-		linux_env_set("modetty0", "38400n8r");
+	if (mips_boot_malta) {
+		sprintf(env_buf, "%un8r", gd->baudrate);
+		linux_env_set("modetty0", env_buf);
+	}
 }
 
 static void boot_jump_linux(bootm_headers_t *images)