arm: s5pc1xx: Move CONFIG_SYS_CLK_FREQ_C1x0 out of CONFIG namespace

The values CONFIG_SYS_CLK_FREQ_C100 and CONFIG_SYS_CLK_FREQ_C110 are
only used in one place and not changed by the board config file.  Move
these out of the CONFIG namespace and in to the CFG namespace.

Signed-off-by: Tom Rini <trini@konsulko.com>