[minip][tcp] fix race introduced by dropping the socket's mutex across tcp_send

-There was a path where the tcp sender is queuing multiple packets in a row but
during the send it received a packet that moved the tx buffer out from underneath it.
[app][inetsrv] make sure the chargen generator buffers at a boundary of the sequence
[app][inetsrv] print some transfer speed statistics
[kernel][vm] allow allocation of physical runs of memory aligned on arbitrary boundaries
[tools][lkboot] fix getsysparam
[target][zybo] factor shared code into an app

Some but not all zybo based projects will want to share some higher
level initialization code, so move that to app/zybo-common and make
the zybo target a bit more bare-bones.
[tools][lkboot] split commandline tool and protocol code
[kernel][vm] remove extra pmm spew
[app][lkboot] provide a means to register additional commands
[make] extend the top level make file to set the root of lk and pass toolchain_prefix via make variable
[app][lkboot] fix lkb_write() for len 65536
[make] allow passing a default project to build if none specified and set the build output root

Change-Id: I5241108517be250535329513996c844f68073564
[platform][zynq] map a bit more of the axi0 aperture

Xilinx IPI projects like to use base addresses 60+MB into the window.
[app][lkboot] fix a dumb bug
[lwip] fix use of sem_post after resched arg was added
[arch][x86] change the logic for figuring out the default TOOLCHAIN_PREFIX

Recent changes to makefile caused TOOLCHAIN_PREFIX to always be set to
something, so change the behavior here to match what arm does.
[platform][alterasoc] get this platform working again after VMM addition
[tools][lkboot] add 'reboot' to the usage output
[arch][arm] fix cache disable routines

-Make sure the stack is kept 8 byte aligned during flush routines
-Properly save and restore cpsr during cache disable
-in PL310, spin on the control register until the disable bit sticks
[platform][zynq] add hook to disable the gem and hard reset it when initializing