spi: cadence-qspi: Fix compilation error in mini u-boot flash reset

spi: cadence-qspi: Fix compilation error in mini u-boot flash reset

When cadence_qspi_versal_flash_reset() function is called in mini
u-boot where there is no firmware support, it is missing defines for
macro's BOOT_MODE_POR_0 & BOOT_MODE_POR_1. Remove them and replace with
already define macro's which have same values as these.

Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@amd.com>
Link: https://lore.kernel.org/r/20221116141155.14788-3-ashok.reddy.soma@amd.com
Signed-off-by: Michal Simek <michal.simek@amd.com>