MIPS: lantiq: Set physical_memsize

physical_memsize is needed by the vpe loader code and the platform
specific code has to define it. This value will be given to the
firmware loaded with the VPE loader. I am not aware of any standard
interface or better value to provide here.
Reported-by: Nkbuild test robot <lkp@intel.com>
Fixes: d9ae4f18 ("MIPS: Lantiq: Activate more drivers in default configuration")
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: John Crispin <john@phrozen.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14908/Signed-off-by: NJames Hogan <james.hogan@imgtec.com>

arch/mips/lantiq/prom.c

@@ -25,6 +25,12 @@
 DEFINE_SPINLOCK(ebu_lock);
 EXPORT_SYMBOL_GPL(ebu_lock);
 
+/*
+ * This is needed by the VPE loader code, just set it to 0 and assume
+ * that the firmware hardcodes this value to something useful.
+ */
+unsigned long physical_memsize = 0L;
+
 /*
  * this struct is filled by the soc specific detection code and holds
  * information about the specific soc type, revision and name