powerpc/mpc8xxx: Enable calculation for fixed DDR chips

We used to have fixed parameters for soldered DDR chips. This patch
introduces CONFIG_SYS_DDR_RAW_TIMING to enable calculation based on timing
data from DDR chip datasheet, implemneted in board-specific files or header
files.

Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/cpu/mpc8xxx/ddr/ddr.h b/arch/powerpc/cpu/mpc8xxx/ddr/ddr.h
index 1e866fe..f59aa33 100644
--- a/arch/powerpc/cpu/mpc8xxx/ddr/ddr.h
+++ b/arch/powerpc/cpu/mpc8xxx/ddr/ddr.h
@@ -14,6 +14,7 @@
 
 #include "common_timing_params.h"
 
+#if defined(CONFIG_DDR_SPD) || defined(CONFIG_SPD_EEPROM)
 /*
  * Bind the main DDR setup driver's generic names
  * to this specific DDR technology.
@@ -25,6 +26,7 @@
 {
 	return ddr_compute_dimm_parameters(spd, pdimm, dimm_number);
 }
+#endif
 
 /*
  * Data Structures
@@ -80,4 +82,9 @@
 extern unsigned int mclk_to_picos(unsigned int mclk);
 extern unsigned int get_memory_clk_period_ps(void);
 extern unsigned int picos_to_mclk(unsigned int picos);
+
+/* board specific function */
+int fsl_ddr_get_dimm_params(dimm_params_t *pdimm,
+			unsigned int controller_number,
+			unsigned int dimm_number);
 #endif