led: qcom-lpg: Fix sleeping in atomic

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

led: qcom-lpg: Fix sleeping in atomic

lpg_brighness_set() function can sleep, while led's brightness_set()
callback must be non-blocking. Change LPG driver to use
brightness_set_blocking() instead.

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/0
preempt_count: 101, expected: 0
INFO: lockdep is turned off.
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 6.1.0-rc1-00014-gbe99b089c6fc-dirty #85
Hardware name: Qualcomm Technologies, Inc. DB820c (DT)
Call trace:
dump_backtrace.part.0+0xe4/0xf0
show_stack+0x18/0x40
dump_stack_lvl+0x88/0xb4
dump_stack+0x18/0x34
__might_resched+0x170/0x254
__might_sleep+0x48/0x9c
__mutex_lock+0x4c/0x400
mutex_lock_nested+0x2c/0x40
lpg_brightness_single_set+0x40/0x90
led_set_brightness_nosleep+0x34/0x60
led_heartbeat_function+0x80/0x170
call_timer_fn+0xb8/0x340
__run_timers.part.0+0x20c/0x254
run_timer_softirq+0x3c/0x7c
_stext+0x14c/0x578
____do_softirq+0x10/0x20
call_on_irq_stack+0x2c/0x5c
do_softirq_own_stack+0x1c/0x30
__irq_exit_rcu+0x164/0x170
irq_exit_rcu+0x10/0x40
el1_interrupt+0x38/0x50
el1h_64_irq_handler+0x18/0x2c
el1h_64_irq+0x64/0x68
cpuidle_enter_state+0xc8/0x380
cpuidle_enter+0x38/0x50
do_idle+0x244/0x2d0
cpu_startup_entry+0x24/0x30
rest_init+0x128/0x1a0
arch_post_acpi_subsys_init+0x0/0x18
start_kernel+0x6f4/0x734
__primary_switched+0xbc/0xc4