PCHG: Don't notify host when there is no soc change
PCHG: Don't notify host when there is no soc change

Currently, the host is notified every time a charging info message
is received from a charger chip. This slows down the host entring
suspend state.

This patch makes the pchg state machine skip notifying the host when
there is no battery level change.

BUG=b:182973695, b:173235954
BRANCH=trogdor
TEST=Stylus connect, disconnect, charge events are triggered as
expected.
TEST=Suspend is entered quickly with a stylus attached.

Signed-off-by: Daisuke Nojiri <fd5f93af191bf7e8f73ea71cc3c0f66b41b1dd49@chromium.org>
Change-Id: If27397a56f8cc636637c0872a00496fee3ca7aa5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2770504

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec