Typo, spelling and grammatical fixes

Minor fixes to documentation and code comments.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c
index 566b4bf..67dbe68 100644
--- a/hw/intc/armv7m_nvic.c
+++ b/hw/intc/armv7m_nvic.c
@@ -172,7 +172,7 @@
         return 10000;
     case 0xd00: /* CPUID Base.  */
         return cpu_single_env->cp15.c0_cpuid;
-    case 0xd04: /* Interrypt Control State.  */
+    case 0xd04: /* Interrupt Control State.  */
         /* VECTACTIVE */
         val = s->gic.running_irq[0];
         if (val == 1023) {