ARM: bootscript: Remove hard-coded rootpath from K+P's tpcboot.cmd

The 'rootpath' can be provided by DHCP server. Removing this line prevents
from overwriting it.

To do that on the DHCP server side (isc-dhcp-server) modify dhcpd.conf
and add 'option root-path "192.168.X.Y:/srv/tftp/rootfs";'

Signed-off-by: Lukasz Majewski <lukma@denx.de>
diff --git a/board/k+p/bootscripts/tpcboot.cmd b/board/k+p/bootscripts/tpcboot.cmd
index 16b93eb..9290317 100644
--- a/board/k+p/bootscripts/tpcboot.cmd
+++ b/board/k+p/bootscripts/tpcboot.cmd
@@ -65,7 +65,6 @@
 #
 # Provide 'boot_nfs' command
 #------------------------------------------------------------
-setenv rootpath "/srv/tftp/KP/rootfs"
 setenv nfsargs "setenv bootargs root=/dev/nfs rw \
        nfsroot=${serverip}:${rootpath},nolock,nfsvers=3"
 setenv addip "setenv bootargs ${bootargs} \