ports_enable array holds port clock information.
It is populated for all SoCs, but ports availability depends on
SoCs. The way it is defined today, location of the port in the
array depends on previous ports definition in SoC CMSIS files.
Though, port index is always the same irrespective of previous
ports availability in the SoC.
This will result in incoherency between port index and clock
information.
Fix this by setting a bogus value if port is not defined.
Return an error if bogus value is read.
Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>
a10d178078