arc: eznps: fix allmodconfig kconfig warning

Fix kconfig warning for arch/arc/plat-eznps/Kconfig allmodconfig:

WARNING: unmet direct dependencies detected for CLKSRC_NPS
  Depends on [n]: GENERIC_CLOCKEVENTS [=y] && !PHYS_ADDR_T_64BIT [=y]
  Selected by [y]:
  - ARC_PLAT_EZNPS [=y]
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Ofer Levi <oferle@mellanox.com>
Cc: linux-snps-arc@lists.infradead.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/plat-eznps/Kconfig

@@ -7,7 +7,7 @@
 menuconfig ARC_PLAT_EZNPS
 	bool "\"EZchip\" ARC dev platform"
 	select CPU_BIG_ENDIAN
-	select CLKSRC_NPS
+	select CLKSRC_NPS if !PHYS_ADDR_T_64BIT
 	select EZNPS_GIC
 	select EZCHIP_NPS_MANAGEMENT_ENET if ETHERNET
 	help