brcmstb PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK issue

[Bjorn Helgaas]

I think caab002d5069 ("PCI: brcmstb: Disable L0s component of ASPM if
requested") introduced a problem:

  #define PCIE_LINK_STATE_L0S             (BIT(0) | BIT(1)) /* Upstr/dwnstr L0s */
  #define PCIE_LINK_STATE_L1              BIT(2)  /* L1 state */

  +#define  PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK   0xc00

  +       /* Don't advertise L0s capability if 'aspm-no-l0s' */
  +       aspm_support = PCIE_LINK_STATE_L1;
  +       if (!of_property_read_bool(pcie->np, "aspm-no-l0s"))
  +               aspm_support |= PCIE_LINK_STATE_L0S;
  +       tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY);
  +       u32p_replace_bits(&tmp, aspm_support,
  +               PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK);


PCIE_LINK_STATE_L0S is two bits, PCIE_LINK_STATE_L1 is one bit, and
the u32p_replace_bits() tries to put all three bits into the two-bit
PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK field.

Interestingly, the compiler only warns about this when !CONFIG_OF
because in that case the of_property_read_bool() stub always returns
"false".  A Kconfig tweak is needed to build this with !CONFIG_OF.