plat(fvp): use generic image fetching functions

Some generic functions have been provided for fetching prebuilt images -
use these for FVP runs.

Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>
Change-Id: I785890c9b0370279230dfd6f71a54bcdc0ebc9c3
diff --git a/rde1edge_utils.sh b/rde1edge_utils.sh
index 662cd8f..ba0b416 100644
--- a/rde1edge_utils.sh
+++ b/rde1edge_utils.sh
@@ -9,8 +9,8 @@
 
 sgi_prebuilts="${sgi_prebuilts:-$css_downloads/sgi/rde1edge}"
 
-fvp_kernels[fvp-sgi-busybox]="$sgi_prebuilts/Image"
-fvp_initrd_urls[fvp-sgi-ramdisk]="$sgi_prebuilts/ramdisk-busybox.img"
+kernel_list[sgi-busybox]="$sgi_prebuilts/Image"
+initrd_list[sgi-ramdisk]="$sgi_prebuilts/ramdisk-busybox.img"
 
 scp_ram_addr=0x0bd80000
 mcp_ram_addr=0x0be00000