[ARM] S3C24XX: Move initialisation code to arch/arm/plat-s3c

[ARM] S3C24XX: Move initialisation code to arch/arm/plat-s3c

We need to add plat-s3c to the build to get the headers
that will go in here once moved from include/asm-arm so
we may as well put some useful common s3c code in here
to stop the errors generated form having nothing built.

The cpu setup is now passed the cpu idcode and the table
of supported cpus to s3c_init_cpu() to abstract the
cpu identification out of the initial io setup.

As well as moving the cpu initialisation code, we move the
map of the board specific items up to the calling code as
none of the map_io() functions actually do anything other
than pass this to iotable_init().

This patch does not rename any of the init functions that
will be common to s3c24xx and any other s3c architectures
as this can be done at a later date as it will touch all
the board support files which use functions such as
s3c24xx_init_clocks() and s3c24xx_init_uarts().

Note, the header arch/arm/plat-s3c24xx/include/plat/cpu.h
still has functions that are used by both the cpu and
board initialisation functions. This means that each board
has definitions specific to the cpu support included and
the vice-versa.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>