With the two new APIs 'plat_arm_sgi_get_platform_id' and
'plat_arm_sgi_get_config_id' that are available now, BL31 need not
depend on hw_config device tree to identify the platform. In addition
to this, the existing hardware description in hw_config can be limited
to use by BL33 and not by the operating system.

So the hardware description from hw_config dts can be moved into
nt_fw_config dts and the use of hw_config dts can be removed.

Change-Id: I873b7e1e72823d3ec5d253a848e85ae724f09e49
Signed-off-by: Chandni Cherukuri <chandni.cherukuri@arm.com>

SGI-Clark.Ares platform is a variant of the SGI-Clark platform. It has
two clusters of four Ares CPUs each. Though very similar to the SGI575
platform, there are subtle differences. HW_CONFIG and TB_FW_CONFIG dts
files have been added.

Change-Id: I740a33cbd1c3b1f1984cb56243b46ad379bab3e6
Signed-off-by: Chandni Cherukuri <chandni.cherukuri@arm.com>