zephyr: Fix Kconfig.charger charge_state_v2 help
zephyr: Fix Kconfig.charger charge_state_v2 help

The menuconfig PLATFORM_EC_CHARGER help section implies that enabling
the PLATFORM_EC_CHARGER option compiles charge_state_v2 code.

Correct the help text to move "enables compilation of charge_state_v2
code" to the appropriate Kconfig sub-option.

BRANCH=none
BUG=b:216366887
TEST=zmake testall

Signed-off-by: Aaron Massey <79529a820df71f45023239a3663736629646cc34@google.com>
Change-Id: I740990525f6b05da9e68293b0a09e27c21e62871
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3576665
Reviewed-by: Jeremy Bettis <4df7b5147fee087dca33c181f288ee7dbf56e022@chromium.org>

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