global: Move remaining CONFIG_SYS_* to CFG_SYS_*

The rest of the unmigrated CONFIG symbols in the CONFIG_SYS namespace do
not easily transition to Kconfig. In many cases they likely should come
from the device tree instead. Move these out of CONFIG namespace and in
to CFG namespace.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/doc/develop/driver-model/migration.rst b/doc/develop/driver-model/migration.rst
index 43665de..fe1ae21 100644
--- a/doc/develop/driver-model/migration.rst
+++ b/doc/develop/driver-model/migration.rst
@@ -99,7 +99,7 @@
 Maintainers should submit patches switching over to using CONFIG_DM_I2C and
 other base driver model options in time for inclusion in the 2021.10 release.
 
-CONFIG_SYS_TIMER_RATE and CONFIG_SYS_TIMER_COUNTER
+CFG_SYS_TIMER_RATE and CFG_SYS_TIMER_COUNTER
 --------------------------------------------------
 Deadline: 2023.01