Input: hyperv-keyboard - remove dependencies on PAGE_SIZE for ring buffer

Define the ring buffer size as a constant expression because it should
not depend on the guest page size.
Signed-off-by: Maya Nakamura <m.maya.nakamura@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/serio/hyperv-keyboard.c

@@ -75,8 +75,8 @@ struct synth_kbd_keystroke {
 
 #define HK_MAXIMUM_MESSAGE_SIZE 256
 
-#define KBD_VSC_SEND_RING_BUFFER_SIZE		(10 * PAGE_SIZE)
-#define KBD_VSC_RECV_RING_BUFFER_SIZE		(10 * PAGE_SIZE)
+#define KBD_VSC_SEND_RING_BUFFER_SIZE		(40 * 1024)
+#define KBD_VSC_RECV_RING_BUFFER_SIZE		(40 * 1024)
 
 #define XTKBD_EMUL0     0xe0
 #define XTKBD_EMUL1     0xe1