rpi: move plat_helpers.S to common
The plat_helpers.S file was almost identical between its RPi3 and RPi4
versions. Unify the two files, moving it into the common/ directory.
This adds a plat_rpi_get_model() function, which can be used to trigger
RPi4 specific action, detected at runtime. We use that to do the RPi4
specific L2 cache initialisation.
Change-Id: I2295704fd6dde7c76fe83b6d98c7bf998d4bf074
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/plat/rpi/common/include/rpi_shared.h b/plat/rpi/common/include/rpi_shared.h
index 6863438..ddf239e 100644
--- a/plat/rpi/common/include/rpi_shared.h
+++ b/plat/rpi/common/include/rpi_shared.h
@@ -36,4 +36,6 @@
/* VideoCore firmware commands */
int rpi3_vc_hardware_get_board_revision(uint32_t *revision);
+int plat_rpi_get_model(void);
+
#endif /* RPI3_PRIVATE_H */