xilinx: common: Add print_cpuinfo() declaration

cpu-info.c defines print_cpuinfo(), but neglected to
include its declaration, causing the following sparse and
compile time warnings:

board/xilinx/common/cpu-info.c:10:5:
warning: no previous prototype for 'print_cpuinfo'
[-Wmissing-prototypes]

Include init.h, which includes the missing declaration.

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com>
Link: https://lore.kernel.org/r/20221004055053.26047-1-venkatesh.abbarapu@amd.com
Signed-off-by: Michal Simek <michal.simek@amd.com>

board/xilinx/common/cpu-info.c

@@ -5,6 +5,7 @@
  */
 
 #include <common.h>
+#include <init.h>
 #include <soc.h>
 
 int print_cpuinfo(void)