ARM: configs: aspeed_g5: Enable AST2600

CONFIG_STRICT_KERNEL_RWX is enabled by default with ARMv7.

Turn on HIGHMEM as the EVB has 2GB of RAM, and not all is usable without
hihgmem.

The SoC contains Cortex A7 supporting VFP and has two CPUs.

Acked-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>