The HWCAPS values are based on the ID registers. Move setting these
to the existing ID register parsing code.

Previously we would need to handle all possible ID field values where
a HWCAP is set, however as most ID fields follow a scheme where when
the field increments it will only add new features meaning we only
need to check if the field is greater than when the HWCAP feature
was added.

While here stop setting HWCAP value that need kernel support, but this
support is missing.