platform: msm_shared: invalidate cache in ext_csd data buffer.

Invalidate cache to read ext_csd data buffer.

Change-Id: Ie40661638496488054c8dd03fe0d23436bc192dc
diff --git a/platform/msm_shared/mmc_sdhci.c b/platform/msm_shared/mmc_sdhci.c
index 12fb661..fd5fbfe 100644
--- a/platform/msm_shared/mmc_sdhci.c
+++ b/platform/msm_shared/mmc_sdhci.c
@@ -686,6 +686,9 @@
 
 	memset(card->ext_csd, 0, sizeof(card->ext_csd));
 
+	/* invalidate any cached buf data (controller updates main memory) */
+	arch_invalidate_cache_range((addr_t) card->ext_csd, 512);
+
 	memset((struct mmc_command *)&cmd, 0, sizeof(struct mmc_command));
 
 	/* CMD8 */