Some of the lines in `platform_mbed.h` only have `FEATURE_PSA`
checked, which is always set for Mbed OS PSA targets but the PSA
APIs are not actually available unless `FEATURE_EXPERIMENTAL_API`
is also enabled. To fix this and improve readability, group all
PSA-related lines and check both macros.
The compiler gave redefinition warnings if
MBEDTLS_ENTROPY_HARDWARE_ALT is defined in the the compile
definitions. A check is added to prevent this warning.
Don't attempt to use default_random_seed unless both PSA and Experimental API
support are enabled. This prevents errors when the Mbed TLS NV Seed feature is
being used on platforms that have PSA enabled by default, but not Experimental
API support by default.
[DEBUG] Output: compilation terminated.
[ERROR] In file included from ./mbed-os/connectivity/mbedtls/include/mbedtls/config.h:31,
from ./mbed-os/connectivity/mbedtls/include/mbedtls/entropy.h:28,
./mbed-os/connectivity/mbedtls/platform/inc/platform_mbed.h:26:10: fatal error: default_random_seed.h: No such file or directory
26 | #include "default_random_seed.h"