msm: emac: Fix clock related warnings

Always status stuck on issue which leads to
many kernel warnings when emac driver
try to disable certain clocks.

Fix the sequence of disabling emac clocks such
that external source is disabled after RCG disabled.

Change-Id: I13d12b33a6e2c7de60fcc2a34df949b064ac21bb
Signed-off-by: Alok Chauhan <alokc@codeaurora.org>