Add Mouse Wheel Scroll Events

This commit add support for mouse wheel scroll events in KVM.
It supports for mouse scroll up/down buttons, by which user can use
mouse wheel functionality.

Testing:
Tested mouse wheel functionality.
Verified mouse wheel scroll up/down functions.

Signed-off-by: Tejas Patil <tejaspp@ami.com>
Change-Id: I7f53f0f203a81b55f2377982571e8f415ed99df2
diff --git a/ikvm_input.hpp b/ikvm_input.hpp
index 558251d..ac54220 100644
--- a/ikvm_input.hpp
+++ b/ikvm_input.hpp
@@ -61,7 +61,7 @@
   private:
     static constexpr int NUM_MODIFIER_BITS = 4;
     static constexpr int KEY_REPORT_LENGTH = 8;
-    static constexpr int PTR_REPORT_LENGTH = 5;
+    static constexpr int PTR_REPORT_LENGTH = 6;
 
     /* @brief HID modifier bits mapped to shift and control key codes */
     static constexpr uint8_t shiftCtrlMap[NUM_MODIFIER_BITS] = {