accel/amdxdna: Declare aie2_max_col as static

Fix the sparse warning:
  symbol 'aie2_max_col' was not declared. Should it be static?

Fixes: c88d332 ("accel/amdxdna: Add hardware resource solver")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202412311028.x2UtcSHm-lkp@intel.com/
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250102212244.1586340-3-lizhi.hou@amd.com

Author: houlz0507

drivers/accel/amdxdna/aie2_pci.c

@@ -25,7 +25,7 @@
 #include "amdxdna_mailbox.h"
 #include "amdxdna_pci_drv.h"
 
-int aie2_max_col = XRS_MAX_COL;
+static int aie2_max_col = XRS_MAX_COL;
 module_param(aie2_max_col, uint, 0600);
 MODULE_PARM_DESC(aie2_max_col, "Maximum column could be used");