You can just apply that patch as-is, but wigyori has added a newer microcode package so you should that one instead.
Just click 'raw' on top and download the resulting patch, apply it, enable the microcode package in make menuconfig, and build the firmware.
FYI, you should see the following in dmesg:
# dmesg|egrep "AMD |microcode"
[ 0.000000] ACPI: DSDT 0x0000000077FB8250 001496 (v02 AMD COREBOOT 00010001 INTL 20140114)
[ 0.000000] ACPI: SSDT 0x0000000077FB9A90 0048A6 (v02 AMD AGESA 00000002 MSFT 04000000)
[ 0.000000] ACPI: SSDT 0x0000000077FBE340 0007C8 (v01 AMD AGESA 00000001 AMD 00000001)
[ 0.320715] smpboot: CPU0: AMD GX-412TC SOC (family: 0x16, model: 0x30, stepping: 0x1)
[ 0.328771] Performance Events: AMD PMU driver.
[ 0.941030] perf: AMD NB counters detected
[ 0.945162] perf: AMD L2I counters detected
[ 0.954295] perf: AMD IBS detected (0x000000ff)
[ 1.220125] ehci-pci 0000:00:13.0: applying AMD SB700/SB800/Hudson-2/3 EHCI dummy qh workaround
[ 2.566929] microcode: CPU0: patch_level=0x07030105
[ 2.571834] microcode: CPU1: patch_level=0x07030105
[ 2.576793] microcode: CPU2: patch_level=0x07030105
[ 2.581735] microcode: CPU3: patch_level=0x07030105
[ 2.586701] microcode: Microcode Update Driver: v2.01 <tigran@aivazian.fsnet.co.uk>, Peter Oruba