x86, boot: Remove misc.h inclusion from compressed/string.c

Given the fact that we removed inclusion of boot.h from boot/string.c
does not look like we need misc.h inclusion in compressed/string.c. So
remove it.

misc.h was also pulling in string_32.h which in turn had macros for
memcmp and memcpy. So we don't need to #undef memcmp and memcpy anymore.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Link: http://lkml.kernel.org/r/1398447972-27896-3-git-send-email-vgoyal@redhat.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>