bootutil/crypto: Fix minor typos in comments for RSA modules

A couple of typos in comments for the newly added RSA modules
need to be assessed.

Signed-off-by: Antonio de Angelis <Antonio.deAngelis@arm.com>
Change-Id: Ia06529adb81215fad796895d7b412b35717b6d65
diff --git a/boot/bootutil/include/bootutil/crypto/rsa.h b/boot/bootutil/include/bootutil/crypto/rsa.h
index d00f11c..581e4ec 100644
--- a/boot/bootutil/include/bootutil/crypto/rsa.h
+++ b/boot/bootutil/include/bootutil/crypto/rsa.h
@@ -92,7 +92,7 @@
     psa_status_t status = PSA_ERROR_INVALID_ARGUMENT;
 
     /* Perform an additional defensive check to compare the modulus of the RSA
-     * key to the expected input to the decryption function, i.e. TLV_ENC_RSA_SZ
+     * key to the expected input of the decryption function, i.e. TLV_ENC_RSA_SZ
      */
     psa_key_attributes_t key_attr =  psa_key_attributes_init();
     status = psa_get_key_attributes(ctx->key_id, &key_attr);
diff --git a/boot/bootutil/src/image_rsa.c b/boot/bootutil/src/image_rsa.c
index d3658fb..34ee85b 100644
--- a/boot/bootutil/src/image_rsa.c
+++ b/boot/bootutil/src/image_rsa.c
@@ -38,7 +38,7 @@
 #include "bootutil/crypto/rsa.h"
 
 /* PSA Crypto APIs provide an integrated API to perform the verification
- * while for other crypto backend we need to implement each step at this
+ * while for other crypto backends we need to implement each step at this
  * abstraction level
  */
 #if !defined(MCUBOOT_USE_PSA_CRYPTO)