[CORE] Add 'alloced_ram' and 'alloced_rom' regions

Currently, we only have 'ram' and 'rom' regions for specifying
memory and this region types forces us to specify host_physcial_addr
in device tree itself.

The above may be functionally good but users will not like to specify
host_physical_addr for every RAM and ROM regions.

This patch adds 'alloced_ram' and 'alloced_rom' device types so that
user can specify RAM and ROM regions which will have host_physical_addr
alloced from host RAM with given alignment order.

Signed-off-by: Anup Patel <anup@brainfault.org>