stm32g4: Clock module driver
stm32g4: Clock module driver

This CL adds support to configure rcc module for stm32g4. The driver
from the F4 family was used as a reference. Support for RTC was not
ported as it's not being used for honeybuns.

The function wait_for_ready() was moved to the common clock file for
the F-family so it would not need to be replicated for G4 as well.

BUG=148493929
BRANCH=None
TEST=verfied that the GPIO, clocks, and EC console over LPUART

Signed-off-by: Scott Collyer <7d40b3eb9e17bf55d972074a5e77a7ea4159f9dd@google.com>
Change-Id: I980c8889965a2e5da401ccd6291079a0bdfa8e4f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2195545
Tested-by: Scott Collyer <7d40b3eb9e17bf55d972074a5e77a7ea4159f9dd@chromium.org>
Reviewed-by: Daisuke Nojiri <fd5f93af191bf7e8f73ea71cc3c0f66b41b1dd49@chromium.org>
Commit-Queue: Scott Collyer <7d40b3eb9e17bf55d972074a5e77a7ea4159f9dd@chromium.org>

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