FW_LOADER: fix kconfig dependency warning on HOTPLUG

Fix kconfig dependency warning for FW_LOADER.

Lots of drivers select FW_LOADER without bothering to depend on
HOTPLUG and/or without selecting HOTPLUG.  A kernel builds fine
when FW_LOADER is enabled, whether HOTPLUG is enabled or not, and
a kernel config file (make oldconfig) is not changed by this patch.
(Yes, drivers/base/firmware_class.c uses interfaces from linux/kobject.h,
which does have some CONFIG_HOTPLUG dependencies, but this patch does
not change that.)

warning: (MICROCODE || MICROCODE_INTEL && MICROCODE || MICROCODE_AMD && MICROCODE || PCMCIA_LOAD_CIS && PCCARD && PCMCIA && EXPERIMENTAL || USB_IRDA && NET && IRDA && USB || BT_HCIBCM203X && NET && BT && USB || BT_HCIBFUSB && NET && BT && USB || BT_HCIBT3C && NET && BT && PCMCIA || BT_MRVL_SDIO && NET
...
!STAGING_EXCLUDE_BUILD && USB && (X86 || ARM) && WLAN || DRM_NOUVEAU && STAGING && !STAGING_EXCLUDE_BUILD && DRM && PCI || TI_ST && STAGING && !STAGING_EXCLUDE_BUILD && RFKILL || DELL_RBU && X86) selects FW_LOADER which has unmet direct dependencies (HOTPLUG)
(5200 byte line reduced a lot)

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>