drivers: marvell: add support for secure read/write of dfx register-set

Since the dfx register set is going to be marked as secure expose dfx
secure read and write function via SiP services. In introduced misc_dfx
driver some registers are white-listed so non-secure software can still
access them.

This will allow non-secure word drivers access some white-listed
registers related to e.g.:  Sample at reset, efuses, SoC type and
revision ID accesses.

Change-Id: If9ae2da51ab2e6ca62b9a2c940819259bf25edc0
Signed-off-by: Grzegorz Jaszczyk <jaz@semihalf.com>
Reviewed-on: https://sj1git1.cavium.com/25055
Tested-by: Kostya Porotchkin <kostap@marvell.com>
Reviewed-by: Kostya Porotchkin <kostap@marvell.com>
diff --git a/drivers/marvell/secure_dfx_access/dfx.h b/drivers/marvell/secure_dfx_access/dfx.h
index 52efbf9..88c4de8 100644
--- a/drivers/marvell/secure_dfx_access/dfx.h
+++ b/drivers/marvell/secure_dfx_access/dfx.h
@@ -13,5 +13,10 @@
 #define MV_SIP_DFX_THERMAL_THRESH	5
 #define MV_SIP_DFX_THERMAL_SEL_CHANNEL	6
 
+#define MV_SIP_DFX_SREAD		20
+#define MV_SIP_DFX_SWRITE		21
+
 int mvebu_dfx_thermal_handle(u_register_t func, u_register_t *read,
 			     u_register_t x2, u_register_t x3);
+int mvebu_dfx_misc_handle(u_register_t func, u_register_t *read,
+			  u_register_t addr, u_register_t val);