Convert CONFIG_SYS_FSL_SFP_BE et al to Kconfig

This converts the following to Kconfig:
   CONFIG_KEY_REVOCATION
   CONFIG_SYS_FSL_SFP_BE
   CONFIG_SYS_FSL_SFP_LE
   CONFIG_SYS_FSL_SFP_VER_3_0
   CONFIG_SYS_FSL_SFP_VER_3_2
   CONFIG_SYS_FSL_SFP_VER_3_4
   CONFIG_SYS_FSL_SRK_LE

This partly means making sure to enable SYS_FSL_ERRATUM_A007186 only for
when CHAIN_OF_TRUST is enabled.

Signed-off-by: Tom Rini <trini@konsulko.com>