hardware:small fixes to SSRAM32 controller

* hold CmdAccept command at 0 for an additional cycle
* gracefully handle additional incoming commands when busy
hardware minor fix to OCP joins

* avoid switching inbetween ongoing commands
* hold CmdAccept at 0 for the respective other side
hardware: minor fix to method cache

* wait for CmdAccept to become 1
hardware: stack cache

* simpler and cleaner interface between core and stack cache
* connect stack cache and buses accordingly
* implement basic stack cache (spill/fill/free/load/store)
emulator: improved tracing output

* print actual address executed (PC)
* print stack cache filling/spilling activity
emulator: improve simulation of UART

* immediately drain TX FIFO after write (avoids slow simulation of UART)
hardware: add a counter register

* helps debugging ;-)
hardware: reduce default stack cache size to 128
simulator: make trace output match emulator (for testing)
emulator: add option -s to trace stack cache spilling/filling
hardware: wait for CmdAccept when spilling in the stack cache
Merge branch 'master' of github.com:t-crest/patmos
sync stack cache with master
segmentation fault removed
stack cache 128 working
stack cache running with 128 k
memory to array
stackcache: Make tracing of stack cache optional in emulator.
stackcache: Revert changes in debugging output of simulator.
stackcache: Revert some build options to defaults.