target/loongarch: check tlb_ps

target/loongarch: check tlb_ps

For LoongArch th min tlb_ps is 12(4KB), for TLB code,
the tlb_ps may be 0,this may case UndefinedBehavior
Add a check-tlb_ps fuction to check tlb_ps,
to make sure the tlb_ps is avalablie. we check tlb_ps
when get the tlb_ps from tlb->misc or CSR bits.
1. cpu reset
   set CSR_PWCL.PTBASE and CSR_STLBPS.PS bits a default value
   from CSR_PRCFG2;
2. tlb instructions.
   some tlb instructions get  the tlb_ps from tlb->misc but the
   value may  has been initialized to 0. we need just check the tlb_ps
   skip the function and write a guest log.
3. csrwr instructions.
   to make sure CSR_PWCL.PTBASE and CSR_STLBPS.PS bits are avalable,
   cheke theses bits and set a default value from CSR_PRCFG2.

Signed-off-by: Song Gao <gaosong@loongson.cn>
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Message-Id: <20250305063311.830674-3-gaosong@loongson.cn>