x86: cpu: introduce scu_ipc_raw_command()

This interface will be used to configure properly some pins on
Merrifield that are shared with SCU.

scu_ipc_raw_command() writes SPTR and DPTR registers before sending
a command to SCU.

This code has been ported from Linux work done by Andy Shevchenko.

Signed-off-by: Georgii Staroselskii <georgii.staroselskii@emlid.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/include/asm/scu.h b/arch/x86/include/asm/scu.h
index 7ce5824..f5ec5a1 100644
--- a/arch/x86/include/asm/scu.h
+++ b/arch/x86/include/asm/scu.h
@@ -6,6 +6,8 @@
 #define _X86_ASM_SCU_IPC_H_
 
 /* IPC defines the following message types */
+#define IPCMSG_INDIRECT_READ	0x02
+#define IPCMSG_INDIRECT_WRITE	0x05
 #define IPCMSG_WARM_RESET	0xf0
 #define IPCMSG_COLD_RESET	0xf1
 #define IPCMSG_SOFT_RESET	0xf2
@@ -23,5 +25,7 @@
 /* Issue commands to the SCU with or without data */
 int scu_ipc_simple_command(u32 cmd, u32 sub);
 int scu_ipc_command(u32 cmd, u32 sub, u32 *in, int inlen, u32 *out, int outlen);
+int scu_ipc_raw_command(u32 cmd, u32 sub, u32 *in, int inlen, u32 *out,
+			int outlen, u32 dptr, u32 sptr);
 
 #endif	/* _X86_ASM_SCU_IPC_H_ */