Route primary MVPD access through SPI engine 3
Route primary MVPD access through SPI engine 3

SPI engine 2 has security enabled, and therefore doesn't support the
LOOP command which we use to read MVPD.

This commit temporarily addresses the issue by routing all MVPD access
to SPI engine 3 (the backup MVPD SEEPROM) which doesn't have the same
security restrictions.

RTC: 258425
Change-Id: Ibc8103b526fc9554d78f2d0b59067651d602c552
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/101789
Tested-by: Jenkins Server <8e3f934e4c44875bc48d33da3ea13d93ba9a233f@us.ibm.com>
Tested-by: Jenkins OP Build CI <e610bd72261d3c0a48f1e8ae36832ab00774d426@us.ibm.com>
Tested-by: FSP CI Jenkins <aa9e4d9ac7cd25905e9c0dd36d4150516e73dd86@us.ibm.com>
Tested-by: Jenkins Combined Simics CI <8312af3886dfc9bb930f549023677220805b137e@us.ibm.com>
Reviewed-by: Deborah L McLemore <1938e6bc52a6fb400ff401d42bc5360c2c7aaa30@us.ibm.com>
Reviewed-by: Ilya Smirnov <2c7a6ec38cfb553b896499595cca9c656159f2a4@us.ibm.com>
Reviewed-by: Daniel M Crowell <912029ca9254ac7b5854e56910561d682e1fa2d0@us.ibm.com>

open-power/hostboot,open-power/hostboot,open-power/hostboot,open-power/hostboot,open-power/hostboot