bsp: autogenerate machine variable from filename

Because we nowadays only use bsp files as a wrapper for
OpenWrt targets, the machine variable got obsolete.
It's only use today is to locate the configuration folder for
a specific bsp.

Instead of explicitly defining this variable, it is now generated
from the filename of the bsp.

Signed-off-by: Fabian Bläse <fabian@blaese.de>
Reviewed-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

bsp/ar71xx-tiny.bsp

@@ -1,4 +1,3 @@
-machine=ar71xx-tiny
 chipset=ar71xx
 subtarget=tiny
 images=("openwrt-${chipset}-${subtarget}-archer-c25-v1-squashfs-*"

bsp/ipq806x-generic.bsp

@@ -1,4 +1,3 @@
-machine=ipq806x-generic
 chipset=ipq806x
 subtarget=generic
 

bsp/mpc85xx-generic.bsp

@@ -1,4 +1,3 @@
-machine=mpc85xx-generic
 chipset=mpc85xx
 subtarget=generic
 

bsp/ramips-mt7621.bsp

@@ -1,4 +1,3 @@
-machine=mt7621-generic
 chipset=ramips
 subtarget=mt7621
 

bsp/ramips-mt76x8.bsp

@@ -1,4 +1,3 @@
-machine=ramips-mt76x8
 chipset=ramips
 subtarget=mt76x8
 images=("openwrt-${chipset}-${subtarget}-tplink_c50-v3-squashfs-*"

buildscript

@@ -362,6 +362,7 @@ loadBSP()
 {
     echo "Working with $(/bin/ls -l selected_bsp | awk '{ print $11 }')"
     . selected_bsp
+    machine=$(basename $(realpath selected_bsp) .bsp)
 }
 
 loadVariant()