bus: mhi: core: Minor style and comment fixes

bus: mhi: core: Minor style and comment fixes

This patch fixes the below checkpatch warnings in MHI bus:

WARNING: Possible repeated word: 'events'
+	/* Process ctrl events events */

WARNING: Missing a blank line after declarations
+			struct mhi_buf_info info = { };
+			buf = kmalloc(len, GFP_KERNEL);

WARNING: Move const after static - use 'static const struct mhi_pm_transitions'
+static struct mhi_pm_transitions const dev_state_transitions[] = {

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>