pd: Add command to get PD chip information

Add a sub-command to the pd command to print PD chip information.
This command gets chip information from non-cros PD chips (e.g.
ANX74xx, PS8751, etc.).

TEST=On Electro, run mosys as follows:
localhost ~ # /tmp/mosys -l pd chip
usage: chip <port>
localhost ~ # /tmp/mosys -l pd chip 0
vendor_id            | 0xaaaa
product_id           | 0x3429
device_id            | 0xad
fw_version           | 0x15
localhost ~ # /tmp/mosys -l pd chip 1
vendor_id            | 0x1da0
product_id           | 0x8751
device_id            | 0x1
fw_version           | 0x37

Change-Id: I8056fcfda3c93a2676147f963183cb6985baaad0
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/439864
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
7 files changed