rockchip: rk3288: add separate TPL STACK address

TPL is at SRAM while other stage is at SDRAM, so it needs
separate STACK.
Signed-off-by: NKever Yang <kever.yang@rock-chips.com>
Reviewed-by: NJagan Teki <jagan@amarulasolutions.com>

arch/arm/mach-rockchip/Kconfig

@@ -95,6 +95,7 @@ config ROCKCHIP_RK3288
 	imply TPL_LIBCOMMON_SUPPORT
 	imply TPL_LIBGENERIC_SUPPORT
 	imply TPL_NEEDS_SEPARATE_TEXT_BASE
+	imply TPL_NEEDS_SEPARATE_STACK
 	imply TPL_OF_CONTROL
 	imply TPL_OF_PLATDATA
 	imply TPL_RAM
@@ -118,6 +119,9 @@ config TPL_TEXT_BASE
 config TPL_MAX_SIZE
 	default 32768
 
+config TPL_STACK
+        default 0xff718000
+
 endif
 
 config ROCKCHIP_RK3328