wil6210: Remove msm platform related code

Current implementation depends on msm-bus driver which
is not merged into mainline kernel therefore
this code is removed

Signed-off-by: Hamad Kadmany <qca_hkadmany@qca.qualcomm.com>
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>