MA-19026 Add config to guard rpmb driver in SPL

MA-19026 Add config to guard rpmb driver in SPL

Android will need rpmb operation in SPL, below commit
guard the rpmb.c build with CONFIG_SPL_SUPPORT_EMMC_RPMB
but didn't add it in the Kconfig:
  commit 2448c34f9fc26d3c459e6e7b28c6357656bfa287
  Author: Heinrich Schuchardt <xypron.glpk@gmx.de>
  Date:   Wed Apr 15 18:28:09 2020 +0200

      drivers: mmc: rpmb: do not build for SPL

      RPMB support is used by the 'mmc rpmb' command and by the OP-TEE
      support.
      We do not need it in SPL.
This commit will add CONFIG_SPL_SUPPORT_EMMC_RPMB defination
and select it by default when trusty is enabled.

Change-Id: I8d3b4481d529828cb03328b826e0e7065104ba46
Signed-off-by: Ji Luo <ji.luo@nxp.com>