linux-firmware: update to the commit from 2018-12-16

It includes e.g. new Broadcom FullMAC firmwares for 4366B1 and 4366C0.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

package/firmware/linux-firmware/Makefile

@@ -11,9 +11,9 @@ PKG_NAME:=linux-firmware
 PKG_RELEASE:=1
 
 PKG_SOURCE_PROTO:=git
-PKG_SOURCE_DATE:=2018-10-18
-PKG_SOURCE_VERSION:=d87753369b82c5f362250c197d04a1e1ef5bf698
-PKG_MIRROR_HASH:=6f3b1d10544609d285a9a47b5bd578bdceb59d86e5d99347e8fa52cd6f3ed66c
+PKG_SOURCE_DATE:=2018-12-16
+PKG_SOURCE_VERSION:=211de1679a68b8ab0f841a8058df35e13e3963f0
+PKG_MIRROR_HASH:=894a13a44c9de58528488682feb3ade582725cd766a16ccaca07089628229d90
 PKG_SOURCE_URL:=https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git
 
 PKG_MAINTAINER:=Felix Fietkau <nbd@nbd.name>