examples.projectspec updates

[nsaulnier-ti]

1. do not hardcode the project name in the postbuild code

e.g., replace $(CG_TOOL_ROOT)/bin/hexpru --diag_wrap=off --array --array:name_prefix=PRU0Firmware -o pru0_load_bin.h empty_am64x-evm_icss_g0_pru0_fw_ti-pru-cgt.out
with
$(CG_TOOL_ROOT)/bin/hexpru --diag_wrap=off --array --array:name_prefix=PRU0Firmware -o pru0_load_bin.h {BuildArtifactFileBaseName}.out

2. the if condition in the postbuild code does not run on both Windows and Linux. Get rid of the conditional, and either document that customer must manually modify this entry if they are using the computer OS that is not supported, or do not add the copyright so we don't even have to have the conditional to begin with.

3. remove dependencies on MCU+ SDK. Postbuild step must be modified to use OPEN_PRU for the copyright. TODO: Check if the compiler includes throw an error if MCU+ SDK is not defined in CCS

4. use the same C code optimization for both project makefiles & example.projectspec

5. Add other action items as needed