fix typos concerning "hierarchy"

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/arch/microblaze/Makefile b/arch/microblaze/Makefile
index 72f6e85..592c707 100644
--- a/arch/microblaze/Makefile
+++ b/arch/microblaze/Makefile
@@ -25,7 +25,7 @@
   ifeq ($(CPU_MAJOR),3)
     CPUFLAGS-1 += -mno-xl-soft-mul
   else
-    # USE_HW_MUL can be 0, 1, or 2, defining a heirarchy of HW Mul support.
+    # USE_HW_MUL can be 0, 1, or 2, defining a hierarchy of HW Mul support.
     CPUFLAGS-$(subst 1,,$(CONFIG_XILINX_MICROBLAZE0_USE_HW_MUL)) += -mxl-multiply-high
     CPUFLAGS-$(CONFIG_XILINX_MICROBLAZE0_USE_HW_MUL) += -mno-xl-soft-mul
   endif