powerpc: Fix crash in early boot on some powermacs
powerpc: Fix crash in early boot on some powermacs

Some powermac machines were crashing in the quiesce firmware call
in prom_init.c because we have just closed the OF stdin device;
notably my 1999 G3 powerbook does this.  To avoid this, don't
close the OF stdin device on powermacs.

Signed-off-by: Paul Mackerras <19a0ba370c443ba08d20b5061586430ab449ee8c@samba.org>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs