greybus: arche-platform: Disable clock as part of driver remove

As part of driver remove (cleanup) function, disable the clock for both
SVC, APB1 & APB2.

Testing Done:
Tested on EVT1 platform with Connect=>disconnect=>connect
iteration, almost close to 100 iterations have passed (demo branch).
And also tested with kernel-only build.

Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>