remove haswell mrc blob (libre raminit stable now)

broadwell mrc is retained, because it's needed on 820 g2

it's no longer needed on haswell, because nri is stable. nri
is short for "native ram initialisation", and libreboot provides
this for: thinkpad t440p, thinkpad w541, dell optiplex 9020 mt,
and dell optiplex 9020 sff

remove, in line with libreboot's binary blob reduction policy

previous revisions, prior to the recent release, stated that
it would be retained for compatibility, but it's really not
right to retain it, because doing so violates libreboot's policy

the recent release excluded mrc-based rom images for haswell
machines, providing only those rom images that use the libre
raminit, while retaining support for mrc in the build system, so
that users could still run the lbmk inject script on older release
roms that use mrc

again: libreboot's binary blob reduction policy is very clear:

https://libreboot.org/news/policy.html

it is a policy that can be summarised, thus:

if a blob can be avoided, it must be avoided.

therefore, we will avoid the Haswell MRC raminit blob

Signed-off-by: Leah Rowe <leah@libreboot.org>

include/mrc.sh

@@ -8,8 +8,6 @@ eval "$(setvars "" MRC_url MRC_url_bkup MRC_hash MRC_board SHELLBALL)"
 
 extract_ref()
 {
-	# refcode needed on broadwell, but not needed on haswell
-
 	# we check mrc twice, because each check only verifies one file,
 	# but refcode is downloaded alongside mrc. in cases where lbmk
 	# erred, downloading only mrc, we must ensure downloading refcode

include/vendor.sh

@@ -96,10 +96,6 @@ download_vendorfiles()
 		    "$E6400_VGA_DL_hash" "$CONFIG_VGA_BIOS_FILE"
 	[ -z "${CONFIG_HAVE_MRC}" ] && return 0
 	fetch "mrc" "$MRC_url" "$MRC_url_bkup" "$MRC_hash" "$CONFIG_MRC_FILE"
-
-	# in case only mrc downloaded before, in a pair of mrc/refcode:
-	[ -n "$CONFIG_REFCODE_BLOB_FILE" ] && fetch "ref" "$MRC_url" \
-	    "$MRC_url_bkup" "$MRC_hash" "$CONFIG_REFCODE_BLOB_FILE"; return 0
 }
 
 fetch()