rockchip: Make ROCKCHIP_COMMON_STACK_ADDR depend on TPL

rockchip: Make ROCKCHIP_COMMON_STACK_ADDR depend on TPL

The stack-pointer addresses used with ROCKCHIP_COMMON_STACK_ADDR expect
that DRAM is initialized by TPL or ROCKCHIP_EXTERNAL_TPL, that SPL has
access to full DRAM and SPL is loaded to/executed from start of DRAM.

Add depends on to ensure use of the ROCKCHIP_COMMON_STACK_ADDR symbol
does not cause problem for any board not using TPL and back-to-BROM
loading of SPL.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>