Rename cpu_reset() to cpu_state_reset()

Frees the identifier cpu_reset for QOM CPUs (manual rename).

Don't hide the parameter type behind explicit casts, use static
functions with strongly typed argument to indirect.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/linux-user/main.c b/linux-user/main.c
index bd47489..01129f2 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -3375,7 +3375,7 @@
         exit(1);
     }
 #if defined(TARGET_I386) || defined(TARGET_SPARC) || defined(TARGET_PPC)
-    cpu_reset(env);
+    cpu_state_reset(env);
 #endif
 
     thread_env = env;