[WCNCR00166497] misc: Refine 5G band support capability acquisition flow

[Description]
5G band support capability acquisition flow may be confused
by parameter RegInfo->ucSupport5GBand without nvram file.

1. Check efuse/HW 5G band capability first,
2. Check nvram setting in wlanLoadManufactureData function then
   (if nvram existed).

Change-Id: Ie6d57e79469500130c7536b9e6fd7b3b5ecb3cda
Signed-off-by: Glenn Tung <glenn.tung@mediatek.com>
CR-Id: WCNCR00166497
Feature: misc
1 file changed