fix(tree): correct some typos

found using codespell (https://github.com/codespell-project/codespell).

Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Change-Id: I1bfa797e3460adddeefa916bb68e22beddaf6373
diff --git a/plat/rockchip/rk3399/drivers/dram/dfs.c b/plat/rockchip/rk3399/drivers/dram/dfs.c
index 816372b..11b0373 100644
--- a/plat/rockchip/rk3399/drivers/dram/dfs.c
+++ b/plat/rockchip/rk3399/drivers/dram/dfs.c
@@ -1696,7 +1696,7 @@
 
 	pll_cnt = ARRAY_SIZE(dpll_rates_table);
 
-	/* Assumming rate_table is in descending order */
+	/* Assuming rate_table is in descending order */
 	for (i = 0; i < pll_cnt; i++) {
 		if (mhz >= dpll_rates_table[i].mhz)
 			break;