powerpc: mpc885: Add CPM USB-SOF microcode for CPM15 ERRATA

MPC885 CPU has the following ERRATA:

	When the USB controller is configured in Host mode, and the
	SOF generation (SFTE=1 in USMOD register) is being used,
	there may be false CRC error indication in other SCCs.
	Although the data is received correctly, the CRC result
	will be corrupted.

Add capability to load the related microcode to fix it.
The microcode binary data is copied from Linux kernel.

Other microcode will be added in following patch so make it
a Kconfig choice.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>