reset: ti-sci: Allow building under COMPILE_TEST

Since commit 043cfff9 ("firmware: ti_sci: Fix compilation failure
when CONFIG_TI_SCI_PROTOCOL is not defined") it is possible to build
reset-ti-sci under CONFIG_COMPILE_TEST.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/20220404094500.2708816-1-p.zabel@pengutronix.de