clk: samsung: remove s3c24xx specific pll bits

With the s3c24xx clk driver gone, the portions of the pll driver
for it can also be removed.

Suggested-by: Chanwoo Choi <cwchoi00@gmail.com>
Link: https://lore.kernel.org/linux-arm-kernel/0e0eff12-d8ea-72e9-d135-4259dda9a750@gmail.com/


Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>