feat(st): use stm32_get_otp_value_from_idx() in BL31

The shadowing of the OTP is done in BL2.
As for BL32 on AARCH32 systems, stm32_get_otp_value_from_idx()
should also use bsec_read_otp() in BL31.

Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Change-Id: Ib406cfc154339e6d3cde3c925bc6e9416d77b689
1 file changed