dt-bindings: clock: gcc-bengal: Remove the throttle clocks

Remove the throttle clocks from the list of clocks managed
by the linux gcc-bengal clock driver.

Change-Id: Iaf74aead4dac73ee297d0a779f57f2f08943fe9c
Signed-off-by: Naveen Yadav <naveenky@codeaurora.org>