ARM: keystone2: Get rid of unused clock files

ARM: keystone2: Get rid of unused clock files

With commit fe772ebd285b ("ARM: keystone2: Use common definition for
clk_get_rate"), we have centralized the clock code into a common clock
logic and the redundant files, unfortunately remained... Clean that
up.

Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>