vendor.sh: handle me_cleaner -p separately

this is a special mode that skips FPTR checks, which is
needed on the topton x2e_n150

we currently set this, when MEclean="n", but we may want to
skip cleaning while still checking FPTR on some boards (in
a future lbmk revision)

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

config/vendor/x2e_n150/pkg.cfg

@@ -17,6 +17,8 @@ XBMKmecleaner="y"
 # me_cleaner currently has to way to validate
 # the result when neutering. simply setting
 # the HAP bit has the same result for users
+
+MEcheck="n" # FPTR checks fail on this board, so skip them
 MEclean="n" # - however:
 
 # we still use me_cleaner, merely to extract, in