refactor(st): move mbedtls config files

The files stm32mp_mbedtls_config-{2,3}.h are moved to
plat/st/common/include directory as they could be shared with other ST
platforms. Their prefixes are changed from stm32mp1 to stm32mp.

Signed-off-by: Yann Gautier <yann.gautier@st.com>
Change-Id: I86e39481b6c8d2689c59eb9a351b77b3d6233b08
3 files changed