ARM: SAMSUNG: register uart clocks to clock lookup list

Samsung uart driver lookups the clock using the connection id 'clk_uart_baud'.
The uart clocks for all Samsung platforms are reorganized to register them
with the lookup name as required by the uart driver.

Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>