Fix: fix parallel build settings for dependencies

- use the "ProcessorCount" module to determine available processors
  and use the value to configure parallel builds instead of constant
  number.
  Pass -DPROCESSOR_COUNT=<n> to cmake to override.
- use cmake --build switches instead of build tool specific parameters
- remove extra cmake run for install step

Change-Id: I04981374be28a14e02dc7c85b230695f412b770e
Signed-off-by: Gyorgy Szing <Gyorgy.Szing@arm.com>
5 files changed