omap4: Export elpidia sdram timings

Individual boards might provide their own emif_get_device_timings function and
use the elpidia timings in their own way, hence those have to be exported.
Signed-off-by: NPaul Kocialkowski <contact@paulk.fr>

arch/arm/cpu/armv7/omap4/sdram_elpida.c

@@ -278,7 +278,7 @@ static const struct lpddr2_ac_timings *elpida_ac_timings[MAX_NUM_SPEEDBINS] = {
 		&timings_elpida_400_mhz
 };
 
-static const struct lpddr2_device_timings elpida_2G_S4_timings = {
+const struct lpddr2_device_timings elpida_2G_S4_timings = {
 	.ac_timings	= elpida_ac_timings,
 	.min_tck	= &min_tck_elpida,
 };

arch/arm/include/asm/arch-omap4/sys_proto.h

@@ -30,6 +30,11 @@ extern const struct dmm_lisa_map_regs ma_lisa_map_2G_x_2_x_2;
 extern const struct lpddr2_device_details elpida_2G_S4_details;
 extern const struct lpddr2_device_details elpida_4G_S4_details;
 #endif
+
+#ifndef CONFIG_SYS_DEFAULT_LPDDR2_TIMINGS
+extern const struct lpddr2_device_timings elpida_2G_S4_timings;
+#endif
+
 struct omap_sysinfo {
 	char *board_string;
 };