meta-gsj: quanta-nvme-powerctrl: Update package README document

Update design, process, test, todo subject included:

1. The new design follow PCI Express Card Electromechanical
   Specification. It could review refer to specification section.
2. The new design and specification don't mention about SSD and LED
   property so delete update led property and nvme_main property steps.
3. Update PCI clock function has been implemented so remove
   TODO subject.
4. Improve initail power-up and service execute sequence.
5. Fix some grammer sentenses.

Change-Id: Ieef4e577b7e81e95ef95e961650de20736992ba6
Signed-off-by: Samuel Jiang <Samuel.Jiang@quantatw.com>
1 file changed