Convert CONFIG_SYS_PBSIZE to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_PBSIZE

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/ls1046afrwy_tfa_SECURE_BOOT_defconfig b/configs/ls1046afrwy_tfa_SECURE_BOOT_defconfig
index 3b303aa..0044442 100644
--- a/configs/ls1046afrwy_tfa_SECURE_BOOT_defconfig
+++ b/configs/ls1046afrwy_tfa_SECURE_BOOT_defconfig
@@ -23,6 +23,7 @@
 CONFIG_BOOTARGS="console=ttyS0,115200 root=/dev/ram0 earlycon=uart8250,mmio,0x21c0500 mtdparts=1550000.spi:1m(rcw),15m(u-boot),48m(kernel.itb);7e800000.flash:16m(nand_uboot),48m(nand_kernel),448m(nand_free)"
 CONFIG_MISC_INIT_R=y
 CONFIG_SYS_MAXARGS=64
+CONFIG_SYS_PBSIZE=532
 CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS=5
 CONFIG_CMD_GPT=y
 CONFIG_CMD_I2C=y