soc: versatile: remove unnecessary static in realview_soc_probe()

Remove unnecessary static on local variables syscon_regmap.
Such variables are initialized before being used, on every
execution path throughout the functions. The static has no
benefit and, removing it reduces the object file size.

This issue was detected using Coccinelle and the following
semantic patch:

@bad exists@
position p;
identifier x;
type T;
@@

static T x@p;
...
x = <+...x...+>

@@
identifier x;
expression e;
type T;
position p != bad.p;
@@

-static
 T x@p;
 ... when != x
     when strict
?x = e;

In the following log you can see the difference in the object file size.
This log is the output of the size command, before and after the code
change:

before:
   text    data     bss     dec     hex filename
   3339    2104     128    5571    15c3 drivers/soc/versatile/soc-realview.o

after:
   text    data     bss     dec     hex filename
   3321    2048      64    5433    1539 drivers/soc/versatile/soc-realview.o

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>