qcacld-3.0: Abstract BMI CE callbacks

As part of WIN BMI modularization, hif_bmi_register_callbacks
are removed from if_pci.c in qcacmn project. As a result,
MCL needs to invoke hif_bmi_register_callbacks in qcacld project.

Fix is to call bus agnostic hif_register_bmi_callbacks method
in bmi_download_firmware.

Change-Id: I72febb02150cf9c672bea4949c53f1b87fa69cdf
CRs-Fixed: 2332266

core/bmi/src/bmi.c

@@ -233,6 +233,8 @@ QDF_STATUS bmi_download_firmware(struct ol_context *ol_ctx)
 
 	if (!hif_needs_bmi(scn))
 		return QDF_STATUS_SUCCESS;
+	else
+		hif_register_bmi_callbacks(scn);
 
 	return bmi_firmware_download(ol_ctx);
 }