perf: RISCV: Fix panic on pmu overflow handler

In the Linux kernel, the following vulnerability has been resolved:

perf: RISCV: Fix panic on pmu overflow handler

(1 << idx) of int is not desired when setting bits in unsigned long
overflowed_ctrs, use BIT() instead. This panic happens when running
'perf record -e branches' on sophgo sg2042.

[ 273.311852] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000098
[ 273.320851] Oops [#1]
[ 273.323179] Modules linked in:
[ 273.326303] CPU: 0 PID: 1475 Comm: perf Not tainted 6.6.0-rc3+ #9
[ 273.332521] Hardware name: Sophgo Mango (DT)
[ 273.336878] epc : riscv_pmu_ctr_get_width_mask+0x8/0x62
[ 273.342291] ra : pmu_sbi_ovf_handler+0x2e0/0x34e
[ 273.347091] epc : ffffffff80aecd98 ra : ffffffff80aee056 sp : fffffff6e36928b0
[ 273.354454] gp : ffffffff821f82d0 tp : ffffffd90c353200 t0 : 0000002ade4f9978
[ 273.361815] t1 : 0000000000504d55 t2 : ffffffff8016cd8c s0 : fffffff6e3692a70
[ 273.369180] s1 : 0000000000000020 a0 : 0000000000000000 a1 : 00001a8e81800000
[ 273.376540] a2 : 0000003c00070198 a3 : 0000003c00db75a4 a4 : 0000000000000015
[ 273.383901] a5 : ffffffd7ff8804b0 a6 : 0000000000000015 a7 : 000000000000002a
[ 273.391327] s2 : 000000000000ffff s3 : 0000000000000000 s4 : ffffffd7ff8803b0
[ 273.398773] s5 : 0000000000504d55 s6 : ffffffd905069800 s7 : ffffffff821fe210
[ 273.406139] s8 : 000000007fffffff s9 : ffffffd7ff8803b0 s10: ffffffd903f29098
[ 273.413660] s11: 0000000080000000 t3 : 0000000000000003 t4 : ffffffff8017a0ca
[ 273.421022] t5 : ffffffff8023cfc2 t6 : ffffffd9040780e8
[ 273.426437] status: 0000000200000100 badaddr: 0000000000000098 cause: 000000000000000d
[ 273.434512] [<ffffffff80aecd98>] riscv_pmu_ctr_get_width_mask+0x8/0x62
[ 273.441169] [<ffffffff80076bd8>] handle_percpu_devid_irq+0x98/0x1ee
[ 273.447562] [<ffffffff80071158>] generic_handle_domain_irq+0x28/0x36
[ 273.454151] [<ffffffff8047a99a>] riscv_intc_irq+0x36/0x4e
[ 273.459659] [<ffffffff80c944de>] handle_riscv_irq+0x4a/0x74
[ 273.465442] [<ffffffff80c94c48>] do_irq+0x62/0x92
[ 273.470360] Code: 0420 60a2 6402 5529 0141 8082 0013 0000 0013 0000 (6d5c) b783
[ 273.477921] ---[ end trace 0000000000000000 ]---
[ 273.482630] Kernel panic - not syncing: Fatal exception in interrupt