ASoC: pcm: increase the hostless buffer size

PAGE_SIZE buffer is not enough in all use cases.This
limits the amount of buffer that can be passed from
userspace. Not increasing this causes failure in pcm_native
when rules are checked against all hw_params passed
from userspace.

Change-Id: Iddc280f78d54a1959be8718055bdb5ef0270653c
Signed-off-by: Anish Kumar <kanish@codeaurora.org>