[MIPS] ARC: Get rid of mips_machgroup

This has not been any serious user of this ill conceived thing since the
original invention in like '95.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/lasat/prom.c

@@ -100,8 +100,6 @@ void __init prom_init(void)
 
 	lasat_init_board_info();		/* Read info from EEPROM */
 
-	mips_machgroup = MACH_GROUP_LASAT;
-
 	/* Get the command line */
 	if (argc > 0) {
 		strncpy(arcs_cmdline, argv[0], CL_SIZE-1);