Let luna88k's bootloader pass RB_GOODRANDOM to the kernel.

Let luna88k's bootloader pass RB_GOODRANDOM to the kernel.

Current bootloader can pass boothowto information to the kernel.  It
also has the capability to load random seed data from /etc/random.seed
already.  So set RB_GOODRANDOM at the bootloader when loadrandom() has
been finished successfully.

Now the kernel says "random: good seed from bootblocks".

Tested by LUNA-88K2 and nono emulator, "Absolutely!" ok miod@