Some brcmstb drivers may be shared with other SoC families. E.g. the
same USB PHY block is shared by brcmstb and BCM4908.
To avoid building brcmstb common code on non-brcmstb platforms we need
stubs for:
1. brcmstb_get_family_id()
2. brcmstb_get_product_id()
(to avoid "undefined reference to" errors).
With this change PHY_BRCM_USB will not have to unconditionally select
SOC_BRCMSTB anymore.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>