rockchip: Improve ARMv7 support for ROCKCHIP_COMMON_STACK_ADDR

rockchip: Improve ARMv7 support for ROCKCHIP_COMMON_STACK_ADDR

A few Rockchip ARMv7 SoCs use 0x60000000 as DRAM base address instead of
the more common 0x0 DRAM base address used on AArch64 SoCs.

Add default options that should work for these ARMv7 SoCs. Same offsets
as before are used, just below 64 MiB. Hex values have also been padded
to improve alignment.

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