Fix the bootrom greybus init
Fix the bootrom greybus init

While doing SPI over greybus implementation, moved some code around
but forgot to do simular thing in the bootrom code. This broke the
BoU of the bootrom. Now fix it.

Testing Done:   BoU in bootrom works.
Bug Number:     Trivial
Review URL:     https://reviews.leaflabs.com/r/2853/
Reviewed by:    Eli Sennesh

Signed-off-by:  Jun Li <4a139eac5426aee89571cee0a0f52cc73d82e960@projectara.com>

projectara/bootrom