target/hppa: New SeaBIOS-hppa version 7

Update SeaBIOS-hppa to version 7 which fixes a boot problem
with Debian-12 install CD images.

The problem with Debian-12 is, that the ramdisc got bigger
than what the firmware could load in one call to the LSI
scsi driver.

Signed-off-by: Helge Deller <deller@gmx.de>
(cherry picked from commit bb9c998)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
(Mjt: pick this one before picking next 34ec3ae "SeaBIOS-hppa version 8")