ARM: S3C24XX: remove unneeded "config SMDK2440_CPU2442"

The Kconfig entry for SMDK2440_CPU2442 was moved from one Kconfig file
to another in commit acf2d41d ("ARM: S3C24XX: Move mach-s3c2440/
pll into mach-s3c24xx/"). In that move it also lost its statement to
select CPU_S3C2442. That was not needed anymore because it now depended
on that same symbol.

But without its select this entry became a nop: enabling it has no
effect, as it changes no code. It can safely be removed.

Fix a related, and trivial, comment typo too.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>