npcx: clock: uart: Add support for npcx7 series ec.

In old clock driver, the relationships between each clock sources are
ambiguous. For example, we treat OSC_CLK and FM_CLK as the same but
sometimes they're not on npcx5. (Only one OSC_CLK definition cannot
present the npcx ec's clock tree very well.) This CL added FM_CLK,
CORE_CLK, and APBx_CLK definitions and used macro functions to confine
the limitation of each clock sources in clock_chip.h to make it more
clearly.

We also modified the uart driver and fixed its source clock to 15MHz so
far in this CL. Since npcx7 already supports uart wake-up mechanism, we
removed the functions of switching pins from UART to GPIO by CHIP_FAMILY
definitions for saving code space.

It also includes:
1. Remove useless CHIP_VERSION definition.
2. Move frequency multiplier values M/N for OSC_CLK to clock_chip.h
3. Add clock_get_fm_freq() for the modules rely on it. Ex, peci.
4. Add clock turbo utilities for npcx7 series.
5. Support uart wake-up mechanism for npcx7 series.

BRANCH=none
BUG=none
TEST=No build errors for all boards using npcx5 series.
     Build poppy board and upload FW to platform. No issues found.
     Passed clock turbo, sysjump and wake-up from UART signals stress
     tests on npcx796f evb.

Change-Id: Id01a8a5d0263f0d2438e6346dfa33bcdef2be56e
Signed-off-by: Mulin Chao <mlchao@nuvoton.com>
Reviewed-on: https://chromium-review.googlesource.com/486821
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>
4 files changed