Undo use of BYTE_x macro
Undo use of BYTE_x macro

The use of the BYTE_x macro in nist_kw did not seem appropriate
in hind sight as it is working with a character array not an int

Signed-off-by: Joe Subbiani <58338b749ceb75cc139988a3309cc9c135482ffd@arm.com>

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