powerpc/mm: Print kernel map details to dmesg

This helps in debugging. We can look at the dmesg to find out
different kernel mapping details.

On 4K config this shows

 kernel vmalloc start   = 0xc000100000000000
 kernel IO start        = 0xc000200000000000
 kernel vmemmap start   = 0xc000300000000000

On 64K config:

 kernel vmalloc start   = 0xc008000000000000
 kernel IO start        = 0xc00a000000000000
 kernel vmemmap start   = 0xc00c000000000000
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/setup-common.c

@@ -831,6 +831,9 @@ static __init void print_system_info(void)
 		pr_info("htab_address      = 0x%p\n", htab_address);
 	if (htab_hash_mask)
 		pr_info("htab_hash_mask    = 0x%lx\n", htab_hash_mask);
+	pr_info("kernel vmalloc start   = 0x%lx\n", KERN_VIRT_START);
+	pr_info("kernel IO start        = 0x%lx\n", KERN_IO_START);
+	pr_info("kernel vmemmap start   = 0x%lx\n", (unsigned long)vmemmap);
 #endif
 #ifdef CONFIG_PPC_BOOK3S_32
 	if (Hash)