ACPI: platform_profile: Avoid initializing on non-ACPI platforms

The platform profile driver is loaded even on platforms that do not have
ACPI enabled. The initialization of the sysfs entries was recently moved
from platform_profile_register() to the module init call, and those
entries need acpi_kobj to be initialized which is not the case when ACPI
is disabled.

This results in the following warning:

 WARNING: CPU: 5 PID: 1 at fs/sysfs/group.c:131 internal_create_group+0xa22/0xdd8
 Modules linked in:
 CPU: 5 UID: 0 PID: 1 Comm: swapper/0 Tainted: G        W           6.15.0-rc7-dirty #6 PREEMPT
 Tainted: [W]=WARN
 Hardware name: riscv-virtio,qemu (DT)
 epc : internal_create_group+0xa22/0xdd8
  ra : internal_create_group+0xa22/0xdd8

 Call Trace:

 internal_create_group+0xa22/0xdd8
 sysfs_create_group+0x22/0x2e
 platform_profile_init+0x74/0xb2
 do_one_initcall+0x198/0xa9e
 kernel_init_freeable+0x6d8/0x780
 kernel_init+0x28/0x24c
 ret_from_fork+0xe/0x18

Fix this by checking if ACPI is enabled before trying to create sysfs
entries.

Fixes: 77be5cac ("ACPI: platform_profile: Create class for ACPI platform profile")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Link: https://patch.msgid.link/20250522141410.31315-1-alexghiti@rivosinc.com


[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>