LDPC: NR_LDPC_NUM_BN_GROUPS_BG2_R15 is incorrect

In nrLDPCdecoder_defs.h#L88, the value of NR_LDPC_NUM_BN_GROUPS_BG2_R15 should be 13 instead of 23.

Current

/** Number of bit node (BN) groups in BG2 for rate 1/5
 A BN group is defined by its number of connected CNs. */
#define NR_LDPC_NUM_BN_GROUPS_BG2_R15 23

Proposed

/** Number of bit node (BN) groups in BG2 for rate 1/5
 A BN group is defined by its number of connected CNs. */
#define NR_LDPC_NUM_BN_GROUPS_BG2_R15 13