MIPS: mm: kmalloc tlb_vpn array to avoid stack overflow

MIPS: mm: kmalloc tlb_vpn array to avoid stack overflow

Owing to Config4.MMUSizeExt and VTLB/FTLB MMU features later MIPSr2+
cores can have more than 64 TLB entries.  Therefore allocate an array
for uniquification instead of placing too an small array on the stack.

Fixes: 35ad7e181541 ("MIPS: mm: tlb-r4k: Uniquify TLB entries on init")
Co-developed-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v6.17+: 9f048fa48740: MIPS: mm: Prevent a TLB shutdown on initial uniquification
Cc: stable@vger.kernel.org # v6.17+
Tested-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Tested-by: Klara Modin <klarasmodin@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>