Minor typos reported by ARM

• 2.3.1 "nor reads from multiple fields"

Should be "nor are reads...", possibly "from multiple adjacent
fields"?

• 2.3.4 "This effects the block capacity and network mac fields"

Should be "This affects the block capacity and network MAC fields"

• 3.1.1 "The driver MUST not accept"

Should be "The driver MUST NOT accept"

• 5.1.6.5.7.2 "a offload"

Should be "an offload"