spi: bcm-qspi: fix SFDP BFPT read by usig mspi read

[ Upstream commit 574bf7bb ]

SFDP read shall use the mspi reads when using the bcm_qspi_exec_mem_op()
call. This fixes SFDP parameter page read failures seen with parts that
now use SFDP protocol to read the basic flash parameter table.

Fixes: 5f195ee7

 ("spi: bcm-qspi: Implement the spi_mem interface")
Signed-off-by: Kamal Dasu <kamal.dasu@broadcom.com>
Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://msgid.link/r/20240109210033.43249-1-kamal.dasu@broadcom.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>