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/run_config/fvp-fip.uefi.debug b/run_config/fvp-fip.uefi.debug
index f7e0a79..1257df8 100644
--- a/run_config/fvp-fip.uefi.debug
+++ b/run_config/fvp-fip.uefi.debug
@@ -6,8 +6,7 @@
 #
 
 post_tf_build() {
-
-	get_uefi_bin
+	url="$uefi_ci_bin_url" filename="uefi.bin" fetch_and_archive
 
 	build_fip BL33="$archive/uefi.bin"
 }