Add ChangeLog entry for CCM_ALT
Add ChangeLog entry for CCM_ALT

Edit the CMAC_ALT ChangeLog entry to mention CCM_ALT which was added
in a sister PR and is being merged together.

Use full name rather than Github id as attribution.

Move the entry under "Features" for better consistency with historical
practice.

ARMmbed/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,NXPmicro/mbedtls,Mbed-TLS/mbedtls,NXPmicro/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,ARMmbed/mbedtls,NXPmicro/mbedtls,NXPmicro/mbedtls,Mbed-TLS/mbedtls