plat/sgi: Bump bl1 RW limit

Increase bl1 RW limit to allow future development.

Change-Id: I3159b36dbaca798b4c4374c1415cd033d6586388
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>

plat/arm/css/sgi/include/sgi_base_platform_def.h

@@ -56,7 +56,7 @@
  * PLAT_ARM_MAX_BL1_RW_SIZE is calculated using the current BL1 RW debug size
  * plus a little space for growth.
  */
-#define PLAT_ARM_MAX_BL1_RW_SIZE	0xB000
+#define PLAT_ARM_MAX_BL1_RW_SIZE	0xC000
 
 /*
  * PLAT_ARM_MAX_ROMLIB_RW_SIZE is define to use a full page