reset: Remove addr parameter from reset_cpu()

Historically, the reset_cpu() function had an `addr` parameter which was
meant to pass in an address of the reset vector location, where the CPU
should reset to.  This feature is no longer used anywhere in U-Boot as
all reset_cpu() implementations now ignore the passed value.  Generic
code has been added which always calls reset_cpu() with `0` which means
this feature can no longer be used easily anyway.

Over time, many implementations seem to have "misunderstood" the
existence of this parameter as a way to customize/parameterize the reset
(e.g.  COLD vs WARM resets).  As this is not properly supported, the
code will almost always not do what it is intended to (because all
call-sites just call reset_cpu() with 0).

To avoid confusion and to clean up the codebase from unused left-overs
of the past, remove the `addr` parameter entirely.  Code which intends
to support different kinds of resets should be rewritten as a sysreset
driver instead.

This transformation was done with the following coccinelle patch:

    @@
    expression argvalue;
    @@
    - reset_cpu(argvalue)
    + reset_cpu()

    @@
    identifier argname;
    type argtype;
    @@
    - reset_cpu(argtype argname)
    + reset_cpu(void)
    { ... }

Signed-off-by: Harald Seiler <hws@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/xen/xenguest_arm64/xenguest_arm64.c b/board/xen/xenguest_arm64/xenguest_arm64.c
index 7d0d782..21363d8 100644
--- a/board/xen/xenguest_arm64/xenguest_arm64.c
+++ b/board/xen/xenguest_arm64/xenguest_arm64.c
@@ -171,7 +171,7 @@
 /*
  * Board specific reset that is system reset.
  */
-void reset_cpu(ulong addr)
+void reset_cpu(void)
 {
 }