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/common/aarch64/plat_ehf.c b/plat/common/aarch64/plat_ehf.c
index da76884..1382690 100644
--- a/plat/common/aarch64/plat_ehf.c
+++ b/plat/common/aarch64/plat_ehf.c
@@ -27,7 +27,7 @@
 #if SPM_MM
 	EHF_PRI_DESC(PLAT_PRI_BITS, PLAT_SP_PRI),
 #endif
-	/* Plaform specific exceptions description */
+	/* Platform specific exceptions description */
 #ifdef PLAT_EHF_DESC
 	PLAT_EHF_DESC,
 #endif