This allows several functions to be static in the files where they
are defined. See temperature.c for an example.

But mainly, the idea is allowing ease addition of features (likely
Kconfig'd ones) for specific WR users, without any modification to the
main function and other generic code.  This will happen soon for snmp,
for example.

We may push this a little further, by moving all shell stuff into
shell.c, the ptp task within ppsi itself, and so on. But now my time
is over.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

This costs anoter 220 bytes in the binary, becuase we now loop among
all temperature providers in order to return data to the caller.

The providers are clustered using an ELF section.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

This commit makes no effect, but it prepares for the following one.
In general, using an intermediate platform-agnostic linker script
when making wrc.o is not bad, so let's do it here.

The main reason why we need it is to force the "KEEP" command for the
".cmd" ELF section, introduced by the next commit.  The alternative to
this would be chaning the main linker script, which is worse in my
opinion.

If we add initcalls or similar stuff later, this bigobj.lds is the
place to do it.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>