i3c: master: Remove set but not used variable 'old_i3c_scl_lim'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/i3c/master/i3c-master-cdns.c: In function 'cdns_i3c_master_do_daa':
drivers/i3c/master/i3c-master-cdns.c:1137:16: warning:
 variable 'old_i3c_scl_lim' set but not used [-Wunused-but-set-variable]

It never used since introdution in commit
  acfab7d324b2 ("i3c: master: Add driver for Cadence IP")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

drivers/i3c/master/i3c-master-cdns.c

@@ -1133,7 +1133,6 @@ static void cdns_i3c_master_upd_i3c_scl_lim(struct cdns_i3c_master *master)
 static int cdns_i3c_master_do_daa(struct i3c_master_controller *m)
 {
 	struct cdns_i3c_master *master = to_cdns_i3c_master(m);
-	unsigned long old_i3c_scl_lim;
 	u32 olddevs, newdevs;
 	int ret, slot;
 	u8 addrs[MAX_DEVS] = { };
@@ -1165,9 +1164,6 @@ static int cdns_i3c_master_do_daa(struct i3c_master_controller *m)
 	newdevs = readl(master->regs + DEVS_CTRL) & DEVS_CTRL_DEVS_ACTIVE_MASK;
 	newdevs &= ~olddevs;
 
-	/* Save the old limitation before add devices. */
-	old_i3c_scl_lim = master->i3c_scl_lim;
-
 	/*
 	 * Clear all retaining registers filled during DAA. We already
 	 * have the addressed assigned to them in the addrs array.