at91sam4: Adding support for the AT91SAM4S4A.

Added the chip definition for the Atmel AT91SAM4S4A. This chip is a 48-pin
package with 256k flash and 64k ram.

Change-Id: I8ada7d5735e31e0ce086f96f5906c7358464245c
Signed-off-by: Thomas Schmid <thomas@rfranging.com>
Reviewed-on: http://openocd.zylin.com/2254
Tested-by: jenkins
Reviewed-by: Paul Fertser <fercerpav@gmail.com>
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>

src/flash/nor/at91sam4.c

@@ -496,6 +496,40 @@ static const struct sam4_chip_details all_sam4_details[] = {
 		},
 	},
 
+	/*atsam4s4a - LQFP48/BGA48*/
+	{
+		.chipid_cidr    = 0x288b09e0,
+		.name           = "at91sam4s4a",
+		.total_flash_size     = 256 * 1024,
+		.total_sram_size      = 64 * 1024,
+		.n_gpnvms       = 2,
+		.n_banks        = 1,
+		{
+/*		.bank[0] = {*/
+		  {
+			.probed = 0,
+			.pChip  = NULL,
+			.pBank  = NULL,
+			.bank_number = 0,
+			.base_address = FLASH_BANK_BASE_S,
+			.controller_address = 0x400e0a00,
+			.flash_wait_states = 6,	/* workaround silicon bug */
+			.present = 1,
+			.size_bytes =  256 * 1024,
+			.nsectors   =  32,
+			.sector_size = 8192,
+			.page_size   = 512,
+		  },
+/*		.bank[1] = {*/
+		  {
+			.present = 0,
+			.probed = 0,
+			.bank_number = 1,
+
+		  },
+		},
+	},
+
 	/*at91sam4sd32c*/
 	{
 		.chipid_cidr    = 0x29a70ee0,