refactor(plat/arm): replace FIP base and size macro with a generic name

Replaced PLAT_ARM_FIP_BASE and PLAT_ARM_FIP_MAX_SIZE macro with a
generic name PLAT_ARM_FLASH_IMAGE_BASE and PLAT_ARM_FLASH_IMAGE_MAX_SIZE
so that these macros can be reused in the subsequent GPT based support
changes.

Change-Id: I88fdbd53e1966578af4f1e8e9d5fef42c27b1173
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
diff --git a/plat/arm/board/fvp/fvp_err.c b/plat/arm/board/fvp/fvp_err.c
index c9b2090..2928b3a 100644
--- a/plat/arm/board/fvp/fvp_err.c
+++ b/plat/arm/board/fvp/fvp_err.c
@@ -24,8 +24,8 @@
 	case -EAUTH:
 		/* Image load or authentication error. Erase the ToC */
 		INFO("Erasing FIP ToC from flash...\n");
-		(void)nor_unlock(PLAT_ARM_FIP_BASE);
-		ret = nor_word_program(PLAT_ARM_FIP_BASE, 0);
+		(void)nor_unlock(PLAT_ARM_FLASH_IMAGE_BASE);
+		ret = nor_word_program(PLAT_ARM_FLASH_IMAGE_BASE, 0);
 		if (ret != 0) {
 			ERROR("Cannot erase ToC\n");
 		} else {