ecc: ecc_make_key_ex, ecc_export_x963, accel_fp_mul, accel_fp_mul2add, ecc_encrypt and ecc_decrypt refactory to reduce stack usage: (1350 bytes - pointer sizes) moved to the heap.
--- ecc_make_key_ex: buf variable moved to the heap; (66 bytes)
--- ecc_export_x963: buf variable moved to the heap; (256 bytes)
--- accel_fp_mul: kb variable moved to the heap; (128 bytes)
--- accel_fp_mul2add: kb variable moved to the heap; (256 bytes)
--- ecc_encrypt: sharedSecret and keys variables moved to the heap; (66 + 256 bytes)
--- ecc_decrypt: sharedSecret and keys variables moved to the heap; (66 + 256 bytes)
fix code format, only spaces added, no code has been modified.