[yocto] PROVIDES problem building u-boot variants

[colin.helliwell at ln-systems.com]

Let's see if I can explain this well...

I created a recipe to build a u-boot variant (for prod'n programming) -
"u-boot-PLATFORM-mfg-sec.bb" - which has :

require u-boot-PLATFORM.inc
UBOOT_MACHINE = "tx6s-8035_mfg_sec_config"
SRC_URI += "file://tx6s-8035_mfg_sec_defconfig"

And 'bitbake u-boot-PLATFORM-mfg-sec' works ok with this. 

Now I want to split this out into two different variants, for different
cpu's.

So I begin by renaming the recipe to "u-boot-PLATFORM_tx6s-mfg-sec.bb",
But 'bitbake u-boot-PLATFORM_tx6s-mfg-sec'  throws:
   "Nothing PROVIDES 'u-boot- PLATFORM_tx6s-mfg-sec'"

Can't spot why this simple renaming is breaking things...?