[POWERPC] PPC: Fix Kconfig whitespace warnings

Fix the following whitespace warnings when compiling with ARCH=ppc

arch/ppc/Kconfig:1207:warning: leading whitespace ignored
arch/ppc/Kconfig:1226:warning: leading whitespace ignored
arch/ppc/Kconfig:1231:warning: leading whitespace ignored

Also fix a typo ("Supprt").

Signed-off-by: Josh Boyer <jdub@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>