spelling: additional

Signed-off-by: Josh Soref <2119212+jsoref@users.noreply.github.com>

src/fw/kernel/memory_layout.c

@@ -218,7 +218,7 @@ void memory_layout_setup_mpu(void) {
   mpu_set_region(&s_microflash_region);
 
   // RAM parts
-  // The background memory map only allows privileged access. We need to add aditional regions to
+  // The background memory map only allows privileged access. We need to add additional regions to
   // enable access to unprivileged code.
 
   mpu_set_region(&s_readonly_bss_region);