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-linux.tc b/run_config/fvp-linux.tc
index 6f18b36..206edcd 100644
--- a/run_config/fvp-linux.tc
+++ b/run_config/fvp-linux.tc
@@ -100,8 +100,8 @@
 }
 
 fetch_tf_resource() {
-	kernel_type="fvp-tc-kernel" get_kernel
-	initrd_type="fvp-tc-ramdisk" get_initrd
+	image="kernel" type="tc-kernel" get_boot_image
+	image="initrd" type="tc-ramdisk" get_boot_image
 
 	# Use SCP binary from SCP build if it exists, or fetch pre-built ones.
 	if [ ! -f "$archive/scp_rom.bin" ]; then