um: Add support for host CPU flags and alignment

1. Reflect host cpu flags into the UML instance so they can
be used to select the correct implementations for xor, crypto, etc.

2. Reflect host cache alignment into UML instance. This is
important when running 32 bit on a 64 bit host as 32 bit by
default aligns to 32 while the actual alignment should be 64.
Ditto for some Xeons which align at 128.

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

arch/um/include/shared/os.h

@@ -187,6 +187,9 @@ int os_poll(unsigned int n, const int *fds);
 extern void os_early_checks(void);
 extern void os_check_bugs(void);
 extern void check_host_supports_tls(int *supports_tls, int *tls_min);
+extern void get_host_cpu_features(
+	void (*flags_helper_func)(char *line),
+	void (*cache_helper_func)(char *line));
 
 /* mem.c */
 extern int create_mem_file(unsigned long long len);