tcpmv2: PE debug level default and string removal
tcpmv2: PE debug level default and string removal

If CONFIG_USB_PD_DEBUG_LEVEL is defined then the
debug level becomes a constant and if it is 0 then
strings will be removed.

BUG=none
BRANCH=none
TEST=verify combinations of CONFIG_USB_PD_DEBUG_LEVEL

Signed-off-by: Denis Brockus <6b21e8190fb5e373363fb95271367073a16474ef@google.com>
Change-Id: If85d9943055eeb004605a914c17d63b7dc314a02
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2176411
Tested-by: Denis Brockus <6b21e8190fb5e373363fb95271367073a16474ef@chromium.org>
Commit-Queue: Denis Brockus <6b21e8190fb5e373363fb95271367073a16474ef@chromium.org>
Reviewed-by: Diana Z <cb2016afc7183e5356c690dc63b4ba817470501a@chromium.org>
Reviewed-by: Jett Rink <9d4aef0593e6843318d99df31597fb6153b89787@chromium.org>
Auto-Submit: Denis Brockus <6b21e8190fb5e373363fb95271367073a16474ef@chromium.org>

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