mtd: spi-nor: sfdp: Rename BFPT_DWORD() macro to SFDP_DWORD()

BFPT_DWORD() converts 1-based indexing to 0-based indexing for C arrays,
and is used in BFPT parse. Per JESD216F.02, the conversion is applicable
to other parameter tables than BFPT. This patch renames the macro to
SFDP_DWORD() so that we can use it for other parameter tables than BFPT.

Suggested-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/e42feac840fe3a31187419e91b2d514d9f259d15.1672026365.git.Takahiro.Kuwano@infineon.com