Bump nios2-gcc      4.1.2 to 4.7.3
     nios2-binutils 2.20  to  2.23
based on Mentor Graphics sourcery site.
Add one patch. (Bump gcc 4.1.2 to 4.7.3, based on Mentor Graphics sourcery site).
Deleting obsolete patches (Bump gcc 4.1.2 to 4.7.3, based on Mentor Graphics sourcery site).