MIPS: Remove redundant CLKDEV_LOOKUP selects

The ATH79 config selects COMMON_CLK already, and the COMMON_CLK config
option already selects CLKDEV_LOOKUP, and CLKDEV_LOOKUP already selects
HAVE_CLK so it's redundant to have these selected again.

Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: <linux-mips@vger.kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lkml.kernel.org/r/20200409064416.83340-6-sboyd@kernel.org