zephyr: drivers: add TCPCI alert related tests
zephyr: drivers: add TCPCI alert related tests

This patch adds unit tests for tcpci_tcpc_alert() function
from driver/tcpm/tcpci.c

BUG=b:184857030
BRANCH=none
TEST=make configure --test zephyr/test/drivers

Signed-off-by: Tomasz Michalec <a547db31280d14f095c760a23a7523d0b1e55fe6@semihalf.com>
Change-Id: I33726ca43bc94588f12467c109cb6b8cc3572d6b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3220338
Tested-by: Tomasz Michalec <c064a6042954d4ba0805003dc021b76413ff1548@google.com>
Commit-Queue: Tomasz Michalec <c064a6042954d4ba0805003dc021b76413ff1548@google.com>
Reviewed-by: Yuval Peress <50dc11c009bd4d7e9d9d15a383c1743ce5ee82ef@google.com>

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