common: charge_state_v2: Add items to .bss.slow.
common: charge_state_v2: Add items to .bss.slow.

BUG=chrome-os-partner:46056
BUG=chrome-os-partner:46063
BRANCH=None
TEST=Enable CONFIG_REPLACE_LOADER_WITH_BSS_SLOW on GLaDOS.  Build,
flash, and verify AP and EC boot.  Plug in charger, issue 'battery'
command.  Verify charging still works and command shows reasonable data.
TEST='sysjump rw' and repeat the above tests.
TEST=make -j buildall tests

CQ-DEPEND=CL:311209

Change-Id: I0661c32b641299d4be685156a4ac725267804a3e
Signed-off-by: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@google.com>
Reviewed-on: https://chromium-review.googlesource.com/311401
Commit-Ready: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@chromium.org>
Tested-by: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@chromium.org>
Reviewed-by: Randall Spangler <62698fdbb84d1779579ee80c3f39fac22017e5bc@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,akappy7/ChromeOS_EC_LED_Diagnostics,coreboot/chrome-ec,coreboot/chrome-ec,akappy7/ChromeOS_EC_LED_Diagnostics,coreboot/chrome-ec,akappy7/ChromeOS_EC_LED_Diagnostics,coreboot/chrome-ec,akappy7/ChromeOS_EC_LED_Diagnostics,akappy7/ChromeOS_EC_LED_Diagnostics