Provided review suggestions

Signed-off-by: Arkadiusz Balys <arkadiusz.balys@nordicsemi.no>

Author: ArekBalysNordic

src/crypto/CHIPCryptoPALmbedTLS.cpp

@@ -783,7 +783,7 @@ P256Keypair::~P256Keypair()
 
 CHIP_ERROR P256Keypair::NewCertificateSigningRequest(uint8_t * out_csr, size_t & csr_length) const
 {
-#if CHIP_CRYPTO_USE_X509
+#if CHIP_CRYPTO_USE_X509 && defined(MBEDTLS_X509_CSR_WRITE_C)
     CHIP_ERROR error = CHIP_NO_ERROR;
     int result       = 0;
     size_t out_length;
@@ -834,7 +834,7 @@ CHIP_ERROR P256Keypair::NewCertificateSigningRequest(uint8_t * out_csr, size_t &
 #else
     ChipLogError(Crypto, "MBEDTLS_X509_CSR_WRITE_C is not enabled. CSR cannot be created");
     return CHIP_ERROR_UNSUPPORTED_CHIP_FEATURE;
-#endif // CHIP_CRYPTO_USE_X509
+#endif // CHIP_CRYPTO_USE_X509 && defined(MBEDTLS_X509_CSR_WRITE_C)
 }
 
 typedef struct Spake2p_Context

src/crypto/CHIPCryptoPALmbedTLSCert.cpp

@@ -46,8 +46,6 @@
 #include <mbedtls/ecp.h>
 #endif // (MBEDTLS_VERSION_NUMBER >= 0x04000000)
 
-#include <mbedtls/x509_csr.h>
-
 #if CHIP_CRYPTO_USE_X509
 #include <mbedtls/x509_crt.h>
 #endif // CHIP_CRYPTO_USE_X509