reboot system if OOM

[edvardxyz]

safety check for buffer allocation failures in the csp_if_cblk_rx function.

Error handling improvements:

• Added a check after calling csp_buffer_get to ensure that a valid buffer was allocated. If allocation fails, the code now calls csp_panic and enters an infinite loop to prevent undefined behavior.

csp_buffer_get_always is in private header

[troelsjessen]

I suggest we keep this on a branch to be included in the STTC release, and request permission from CSP to use csp_get_buffer_always from L2 interfaces not defined internally in libcsp

[johandc]

Yes. Buffer get always was designed for exactly this. If the uplink CBLK interface cannot allocate a CSP buffer, its best to flush everything by rebooting.