apps/examples: Add path option to SPI Slave test

[eren-terzioglu]

Summary

• apps/examples: Add path option to SPI Slave test

Add path option to spislv_test example

Impact

Impact on user: Yes. Users can test different SPI slave interface just changing command
Impact on build: No.
Impact on hardware: No.
Impact on documentation: No.
Impact on security: No.
Impact on compatibility: No.

Testing

esp32c6-devkitc:spislv config used.

Building

Command to build:

make -j distclean && ./tools/configure.sh esp32c6-devkitc:spislv && make -j && make download ESPTOOL_PORT=/dev/ttyUSB0

Running

spislv -p /dev/spislv0 -x 2 abba and spislv -p /dev/spislv2 -x 2 abba commands used to test

Output

Here is the output

nsh> spislv -p /dev/spislv0 -x 2 abba
Error: Failed to open /dev/spislv0: No such file or directory
nsh> spislv -p /dev/spislv2 -x 2 abba
Slave: Queuing 2 bytes for sending to master: AB BA 

[acassis]

@eren-terzioglu why is it spislv2 instead of spislv0 ?