MIPS: Fix address type used for early memory detection.

In 'early_parse_mem' the data type used for the start
and size of a memory region specified on the command line
is incorrect. If 64-bit addressing is used, the value
gets truncated.
Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8456/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/setup.c

@@ -493,7 +493,7 @@ static int usermem __initdata;
 
 static int __init early_parse_mem(char *p)
 {
-	unsigned long start, size;
+	phys_t start, size;
 
 	/*
 	 * If a user specifies memory size, we