phosphor: react to fitimage artifact rename

poky rev d0a8532abb changed the naming conventions for fit image
artifacts.  Update where we look for fit artifacts to match.

Change-Id: I15c489faf3c284ef5cae255553356f1a30bda067
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/classes/image_types_phosphor.bbclass b/classes/image_types_phosphor.bbclass
index 2437390..1edf3a3 100644
--- a/classes/image_types_phosphor.bbclass
+++ b/classes/image_types_phosphor.bbclass
@@ -9,7 +9,7 @@
 # The reference BMC software update implementation.
 
 # Image composition
-FLASH_KERNEL_IMAGE ?= "fitImage-${INITRAMFS_IMAGE}-${MACHINE}.bin"
+FLASH_KERNEL_IMAGE ?= "fitImage-${INITRAMFS_IMAGE}-${MACHINE}-${MACHINE}"
 FLASH_KERNEL_IMAGE_df-obmc-ubi-fs ?= "fitImage-${MACHINE}.bin"
 
 IMAGE_BASETYPE ?= "squashfs-xz"